The Amazon Kindle is a series of e-book readers designed and marketed by Amazon.com. Amazon Kindle devices enable users to shop for, download, browse, and read e-books, newspapers, magazines, blogs, and other digital media via wireless networking. The hardware platform, developed by Amazon.com subsidiary Lab126, began as a single device and now comprises a range of devices, including dedicated e-readers with E Ink electronic paper displays, and Android-based tablets with color LCD screens.
The Kindle name was devised by branding consultant Michael Cronan who was asked by Lab 126 to name the product. Cronan and partner Karin Hibma suggested Kindle, meaning to light a fire. They felt this was an apt metaphor for reading and intellectual excitement.
Kindle hardware has evolved from the original Kindle introduced in 2007 and a Kindle DX line (with a larger screen) introduced in 2009. The range now includes devices with a keyboard (Kindle Keyboard), devices with touch-sensitive screens (Kindle Paperwhite), a tablet computer with a reader app and a color display (Kindle Fire), and a low-priced model with an on-screen keyboard (Kindle).
Amazon has also introduced Kindle software for use on various devices and platforms, including Microsoft Windows, iOS, BlackBerry, Mac OS X (10.5 or later, Intel processor only), Android, webOS, and Windows Phone. Amazon also has a “cloud” reader to allow users to read and purchase Kindle books from a web browser.
Content for the Kindle can be purchased online and downloaded wirelessly in some countries, using either standard Wi-Fi or Amazon’s 3G “Whispernet” network. Whispernet is accessible without any monthly fee or wireless subscription, although fees can be incurred for the delivery of periodicals and other content when roaming internationally beyond the customer’s home country. Through a service called “Whispersync,” customers can synchronize reading progress, bookmarks, and other information across Kindle hardware and other mobile devices.
In the last three months of 2010, Amazon announced that in the United States, their e-book sales had surpassed sales of paperback books for the first time.
Amazon released the Kindle, the first generation Kindle device on November 19, 2007, for US$399. It sold out in five and a half hours. The device remained out of stock for five months until late April 2008.
It is the only Kindle with expandable memory, via an SD card slot.
The device features a 6 inches (diagonal) 4-level grayscale display, with 250 MB of internal memory, which can hold approximately 200 non-illustrated titles. It also has a speaker and headphone jack that allows the user to access audio files on Kindle.
The device’s Whispernet feature was co-designed with Qualcomm, and Kindle was the first device to include free nationwide 3G access to download books from the Amazon web store. Amazon did not sell the first-generation Kindle outside the United States. Plans for a launch in the UK and other European countries were delayed by problems with signing up suitable wireless network operators.
On February 10, 2009, Amazon announced the Kindle 2. It became available for purchase on February 23, 2009. The Kindle 2 features a text-to-speech option to read the text aloud, and 2 GB of internal memory of which 1.4 GB is user-accessible. By Amazon’s estimates, the Kindle 2 can hold about 1,500 non-illustrated books. Unlike the first-generation Kindle, Kindle 2 does not have a slot for SD memory cards. It was slimmer than the original Kindle.
To promote the new Kindle, author Stephen King made UR, his then-new novella, available exclusively through the Kindle Store.
According to an early review by iFixIt, the Kindle 2 features a Freescale 532 MHz, ARM-11 90 nm processor, 32 MB main memory, 2 GB moviNAND flash memory and a 3.7 V 1,530 mAh lithium polymer battery.
On July 8, 2009, Amazon reduced price of the Kindle 2 from the original $359 to $299. On October 7, 2009, Amazon further reduced the price of the Kindle 2 to $259. The Kindle 2 had a manufacturing materials cost estimated at $185.49, in 2009 by iSuppli.
On October 22, 2009, Amazon stopped selling the original Kindle 2 in favor of the international version it had introduced earlier in the month. On November 24, 2009, Amazon released a firmware update for the Kindle 2 that it said increased battery life by 85% and introduced native PDF support.
On October 7, 2009, Amazon announced an international version of the Kindle 2 with the ability to download new titles in over 100 countries. It became available October 19, 2009. The international Kindle 2 is physically very similar to the U.S.-only model, although it uses a different mobile network standard.
The original Kindle 2 used CDMA2000 for use on the Sprint network. The international version used standard GSM and 3G GSM, enabling it to be used on AT&T’s U.S. mobile network and internationally in 100 other countries.
The international version of the Kindle 2 is believed to have a noticeably higher contrast screen, although Amazon does not advertise this. Another review done by Gadget lab, disputes this and actually states that the font appears to be fuzzier than that of the first generation kindle. The review goes on to say that changes to the Kindle 2 have made it tougher to read the smaller font sizes that most books use. Writers on another website discuss how the font size is at times worse than that of the first-generation Kindle. It appears that whether the Kindle 2 is clearer or fuzzier than the prior model depends on the font size. These issues became moot when Amazon sourced a higher contrast E Ink technology it dubbed “E Ink Pearl” and which it used in all of its e-reader devices thereafter.
On October 22, 2009, Amazon lowered the price on the international version from $279 to $259 and discontinued the U.S.-only model. On June 21, 2010, hours after Barnes & Noble lowered the price of its Nook, Amazon lowered the price of the Kindle 2 to $189.
Amazon announced the Kindle DX on May 6, 2009. This device has a larger screen than the standard Kindle and supports simple PDF files. It was also the thinnest Kindle to date and offers an accelerometer, which enables the user to seamlessly rotate pages between landscape and portrait orientations when the Kindle DX is turned on its side. It is marketed as more suitable for displaying newspaper and textbook content. The device can only connect to Whispernet in the United States. It can be distinguished from the later International version by a serial number starting with “B004”.
Since January 19, 2010, the Kindle DX International has shipped in 100 countries. The Kindle DX comes with a 9.7-inch E Ink screen instead of the 6-inch Kindle screen. It has support for international 3G wireless, and its serial number will start with “B005”.
On July 1, 2010, Amazon released the Kindle DX Graphite, a revision of the DX. As well as dropping the price from $489 to $379, the new Kindle DX has an E Ink display with 50% better contrast ratio (due to new E Ink Pearl technology) and comes only in a “graphite” case color. It is speculated the case color change is to improve contrast ratio perception further, as some users found the prior white casing highlighted that the E Ink background is light gray and not white. Like the prior Kindle DX, it does not have a Wi-Fi connection. Its serial numbers start with “B009”. The DX Graphite (DXG) is a mix of third-generation hardware and second-generation software. The CPU is of the same speed as Kindle 3 but is of a different revision. Even though DX Graphite has a larger case, it has only a half the system memory (128MB) of the Kindle 3 (256 MB). Due to these hardware differences, the DX Graphite runs the same firmware as Kindle 2. Therefore, DX Graphite cannot display international fonts (such as the Cyrillic font, Chinese, or any other non-Latin font), and PDF and the web browser are limited to Kindle 2 features. The Kindle DX was withdrawn from sale in October 2012, but in September 2013 was made available again in the US and internationally, with the 3G data free to access the Kindle Store and Wikipedia. Loading personal documents by USB is free, but sending them via 3G is about $1 per megabyte in Ireland. It has battery life of about one week with 3G and two to three weeks with wireless off. It does not have WiFi capabilities. Text to Speech and MP3 playback are supported.
Amazon announced the third generation of the Kindle, later called the Kindle Keyboard, on July 28, 2010. While Amazon does not officially add numbers to the end of each Kindle denoting its generation, reviewers, customers and press companies often refer to this updated Kindle as the “K3” or the “Kindle 3”. The third generation Kindle had a 6 inches (15 cm) screen with a resolution of 600×800 (167 PPI).
The Kindle Keyboard is available in two versions. One of these, the Kindle Wi-Fi, was initially priced at $139 / GB£111 and connects to the Internet exclusively via Wi-Fi networks. The other version, considered a replacement to the Kindle 2, was priced at $189 / £152 and includes both 3G and Wi-Fi connectivity. (currently unavailable in UK ) The built-in free 3G connectivity uses the same wireless signals that cell phones use, allowing it to download and purchase content from any location with cell service. The Kindle Keyboard with 3G is available in two colors: classic white and graphite. Both models use the newer E Ink “Pearl” display, which has a higher contrast than prior displays and a faster refresh rate. However, it remains slower than traditional LCDs.
The Kindle Keyboard uses a Freescale i. MX353 applications processor, Freescale MC13892 power management chip, Epson E INK controller, and Samsung DRAM and flash. Other hardware changes include a larger 1,750 mAh lithium-ion polymer battery, AnyDATA DTP-600W 3G GSM modem, and Atheros AR6102G 802.11bg Wi-Fi chip.
The third-generation Kindle is 0.5 in shorter and 0.5 in narrower than the Kindle 2. It supports additional fonts and international Unicode characters and has a Voice Guide feature with spoken menu navigation. Experimental features include a browser based on the popular WebKit rendering engine (but browser may be limited to 50MB of 3G per month to web sites other than Amazon and Wikipedia in territories outside of the United States), Text-to-Speech that can read aloud the text from books and other content, and an MP3 player. Internal memory is expanded to 4 GB, with approximately 3 GB available for user content. Battery life is advertised at up to two months of reading half an hour a day on a single charge with the wireless turned off, which amounts to roughly 30 hours.
Amazon began accepting pre-orders for the new Kindle as soon as it was announced and began shipping the devices on August 27, 2010, in the United States and United Kingdom. With the announcement of the Kindle Keyboard, Amazon also launched an Amazon.co.uk version of the Kindle store. On August 25, 2010, Amazon announced that the Kindle 3 was the fastest-selling Kindle ever.
In late January 2011, Amazon announced that digital books were outselling their traditional print counterparts for the first time ever on its site, with an average of 115 Kindle editions being sold for every 100 paperback editions.
An ad-supported version, the “Kindle with Special Offers” was introduced on May 3, 2011, with a price reduction of $25 less at $114. On July 13, 2011, Amazon announced that due to a sponsorship agreement with AT&T, the price of the Kindle 3G with Special Offers would be lowered to $139, $50 less than the Kindle 3G. With the 2011 Kindle announcement, the price of the “Kindle Keyboard with Special Offers” was reduced to $99.
The Kindle Keyboard generally received good reviews after launch. In their Kindle Keyboard Review, Review Horizon describes it as offering “the best reading experience in its class” while Engadget states, “In the standalone category, the Kindle is probably the one to beat”.
After the introduction of the low priced Kindle version, and Kindle Touch and Kindle Fire readers in September 2011 Amazon began describing the older Kindle version as the ‘Kindle Keyboard’ instead of the Kindle 3. At the time, 3G is not available for all countries.
Amazon announced the fourth-generation Kindle on September 28, 2011 ($79 ad-supported, $109 no ads). Retaining the 6 inch e-ink display of the previous Kindle model as well as Amazon’s experimental web-browsing capability with Wi-Fi, the fourth-generation Kindle features a slight reduction in weight and size in a silver-grey bezel, as well as nine hard keys, a cursor pad, an on-screen rather than physical keyboard, a flash storage capacity of 2 GB, and an estimated one month battery life.
Amazon announced a touchscreen Kindle, called the Kindle Touch, on September 28, 2011, available with Wi-Fi ($99 ad-supported, $139 no ads) or Wi-Fi/3G connectivity ($149 ad-supported, $189 no ads). Via 3G the device is able to connect to the Kindle Store, download books and periodicals, and access Wikipedia. Experimental web browsing (outside of Wikipedia) on Kindle Touch 3G is only available over Wi-Fi. (Kindle Keyboard continues without this restriction). The usage of the 3G data is limited to 50MB per month. The device uses the same 6 inch E-ink screen of the previous Kindle model, with the addition of an infrared touch-screen control. Like its predecessor, the Kindle Touch has a capacity of 4 GB and battery life of two months. The Kindle Touch began to ship on November 15, 2011 (U.S. only). Amazon announced in March 2012 that the device would be available in the UK, Germany, France, Spain and Italy on April 27, 2012. In January 2013, Amazon released the 5.2.0 firmware that updated the operating system to match the Paperwhite’s interface with the Touch’s MP3/audiobook capabilities remaining.
Amazon announced a new version of the regular Kindle and the Kindle Paperwhite on September 6, 2012. The Kindle 5 was released on September 6 ($69 ad-supported, $89 no ads). The Kindle has a black bezel (compared to the Kindle 4, which was available in silver-grey), better contrast, and hand-tuned fonts. It is claimed to have 15% faster page loads. It has a 167 PPI display and is the lightest Kindle at 5.98 oz (170 g).
The Kindle Paperwhite (1st generation) was released on October 1, 2012 in the United States. It has a 6 in, 212 PPI display (an almost-XGA resolution of 758×1024) with built-in LEDs to illuminate the screen, and has 2GB of storage (1.25GB usable). It was available in Wi-Fi ($119 ad-supported, $139 no ads) and Wi-Fi + 3G ($179 ad-supported, $199 no ads) models, with the ad-supported options only available in the United States. The light is one of the main features of the Paperwhite, but the light level must be adjusted manually. The 3G access restrictions are the same as the Kindle Touch, and usage of the 3G data is limited to 50 MB per month. Additional data can be purchased. Battery life is advertised at up to eight weeks of reading with half an hour per day with wireless off and constant light usage; this usage equals 28 hours. It includes the experimental web browser with the same 3G data restrictions as the Kindle Touch. The official leather cover for the Paperwhite uses the hall effect sensor in the device that detects when the cover is closed/opened to turn the screen off/on respectively. This device was the first Kindle to track one’s reading speed to estimate when one will finish a chapter or book; this feature was later included with updates to the other Kindles and Kindle Fire tablets. The Kindle Paperwhite lacks physical buttons for page turning and does not do auto-hyphenation. Except for the lock-screen/power button at its bottom, it relies solely on the touchscreen interface. In November 2012, Amazon released the 5.3.0 update that allowed users to turn off recommended content on the home screen in Grid View (allowing two rows of user content) and included general bug fixes. In March 2014, the Paperwhite 5.4.4 update was released that added Goodreads integration, Kindle FreeTime to restrict usage for children, Cloud Collections for organization and Page Flip for scanning content without losing your place, which closely matches the Paperwhite 2’s software features.
The Kindle Paperwhite was released in most major international markets in early 2013, with Japan’s version including 4GB of storage, and in China on June 7, 2013.
Engadet praised the Paperwhite, giving it a 92 out of 100. The reviewer liked the front-lit display, high contrast, and useful software features, but did not like that it is less comfortable to hold than the Nook, the starting price includes ads, and it has no expandable storage.
Shortly after release, some users complained about the lighting implementation on the Kindle Paperwhite. While not widespread, some users found the lighting to be inconsistent, causing the bottom edge to cast irregular shadows. Also, some users complained that the light can only be dimmed, not turned off completely.
Amazon announced the Kindle Paperwhite (2nd generation), marketed as the “All-New Kindle Paperwhite” and colloquially referred to as the Paperwhite 2, on September 3, 2013; the Wi-Fi version was released in the USA on September 30, 2013 ($119 ad-supported, $139 no ads), and the 3G/Wi-Fi version was released in the USA on November 5, 2013 ($189 ad-supported, $209 no ads).
The Paperwhite 2 features a higher contrast E Ink Carta display technology, improved LED illumination, 25% faster processor (1 GHz) that allows for faster page turns, and better response to touch input compared to the original Paperwhite. It has the same 6″ screen with 212 PPI and bezel as the original Paperwhite. The software features dictionary/Wikipedia/X-Ray look-up, Page Flip that allows the user to skip ahead or back in the text in a pop-up window and go back to the previous page, and Goodreads social integration.
The Paperwhite 2 uses the same experimental web browser with the same 3G data usage restrictions as previous Kindles; there are no usage restrictions when using Wi-Fi. The official leather cover for the Paperwhite 2 is the same item as was used for the original Paperwhite. It turns the screen on or off when it is opened or closed.
The Kindle Paperwhite 2 was released in most major international markets by the middle of 2014 and this released model includes 4GB of storage. As of September 2014, the US version of the Paperwhite 2 includes 4GB of storage.
Engadget gave the Paperwhite 2 a 93 out of 100, saying while the “all-new” Paperwhite does not offer many new features compared to the original Paperwhite, the improved frontlight and software functions make a great reading experience even better.
Amazon announced a new upgraded basic Kindle and the new Kindle Voyage on September 18, 2014. The basic Kindle 6 will be released in October 2014 ($79 ad-supported, $99 no ads). It is the first basic Kindle to use a touchscreen for navigating books, and there is no longer a touchscreen-less Kindle choice. It is the first basic Kindle available in international markets such as Japan and China.
The Kindle Voyage will be released on October 21, 2014 in the United States. It has a 6-inch, 300 PPI display (the highest resolution available in ereaders) with adaptive LEDs to illuminate the screen depending on the environment, and has 4GB of storage (3GB usable). It will be available in Wi-Fi ($199 ad-supported, $219 no ads) and Wi-Fi + 3G ($269 ad-supported, $289 no ads) models. It features a new design of flush glass screen and rear power button, similar to the Kindle Fire HDX. The Voyage uses a new method of turning pages, called ‘PagePress’. There are sensors on either side of the screen and if pressed it turns the page.
The Kindle Voyage sold Amazon China has a “special limited edition” cased in a gift box with add-ons of a power adapter, a leather protective cover and a 100 yuan gift card.
Amazon announced Kindle Fire, an Android-based tablet that uses a fork of Android called Fire OS 1 on September 28, 2011. It was released for $199 and has a 7 in IPS color touchscreen display. This was the first Kindle without an E Ink display. However, unlike previously released Kindles, it has no 3G option, but only Wi-Fi. It has 8 GB of storage and a projected battery life of up to eight hours. In September 2012, the Kindle Fire was refreshed to have more RAM, a faster processor, an updated OS, and price reduced to $159.
The Kindle Fire HD, announced on September 6, 2012, is the second generation of Amazon’s color touchscreen Kindle Fire tablet line. It is available in two form factors, 7 in and 8.9 in screen sizes. Introductory pricing was at $199 and $299, respectively for the 16 GB versions; both Fire HD were sold at cost. The 7 in version was released on September 14, while the 8.9 in model (with either Wi-Fi or 4G model) was released on November 20, 2012. In October 2013, the Fire HD 7 in was refreshed using the Fire HDX unibody and had its price reduced to $139.
The Kindle Fire HDX, announced on September 25, 2013, is the third generation of Amazon’s Kindle Fire tablet line. It is available in 7 in and 8.9 in screen sizes, with introductory prices of $229 and $379, respectively, for the 16 GB version with special offers. Both tablets are also available in 32 and 64 GB versions.
Amazon released a “Kindle for PC” application in late 2009, available as a free download for Microsoft Windows 8, 7, Vista, and XP. This application allows thousands of books to be read on a personal computer in color, with no Kindle unit required, as e-books can simply be purchased from Amazon’s store. Amazon later released a version for the Apple Macintosh, in early 2010. In June 2010, Amazon released a “Kindle for Android” version. With the Google Android application release, versions for the Apple iPhone, the iPad, Windows and Mac computers, and BlackBerry cellphones are also available. In January 2011, Amazon released Kindle for MS Windows Phone 7. In July 2011, Kindle for HP TouchPad (running under webOS) was released in the US as a beta version. In August 2011, Amazon released an HTML5 based webapp supporting the Chrome, Firefox and Safari browsers called Kindle Cloud Reader. As of 2013, Amazon has expressed no interest in releasing a separate application for the GNU/Linux operating system, however the Cloud Reader can be used in Linux using the browser.
On April 17, 2014, Samsung announced it would discontinue its ebook store effective July 1, 2014 and would partner with Amazon for the Kindle for Samsung app, which would permit Samsung Galaxy users using Android 4.0 or higher to use Amazon’s catalog, and would add a free book service, Samsung Book Deals, that would allow users of the app to choose one free ebook monthly from a selection provided by Amazon.
Specific Kindle sales numbers are not released by the company; however, Jeff Bezos, founder and CEO of Amazon.com, stated in a shareholders’ meeting in January 2010 that “millions of people now own Kindles”. According to anonymous inside sources, over three million Kindles had been sold as of December 2009, while external estimates, as of Q4-2009, place the number at about 1.5 million. According to James McQuivey of Forrester Research, estimates are ranging around four million, as of mid-2010. On March 6, 2011, AT&T stores officially started sales of the Amazon Kindle. 
In 2010, Amazon remained the undisputed leader in the e-reader category, accounting for 59% of e-readers shipped, and it gained 14 percentage points in share. According to an International Data Corporation (IDC) study from March 2011, sales for all e-book readers worldwide reached 12.8 million in 2010; 48% of them were Kindles.
In December 2011, Amazon announced that customers had purchased “well over” one million Kindles per week since the end of November 2011; this includes all available Kindle models and also the Kindle Fire tablet. IDC estimated that the Kindle Fire sold about 4.7 million units during the fourth quarter of 2011. Pacific Crest estimated that the Kindle Fire models sold six million units during Q4 2012.
Morgan Stanley estimates that Amazon sold $3.57 billion worth of Kindle e-readers and tablets in 2012, $4.5 billion in Kindle device sales in 2013 and $5 billion in Kindle device sales in 2014.
Content from Amazon and some other content providers is primarily encoded in Amazon’s proprietary Kindle format (AZW, KF8). It is also possible to load content in various formats from a computer by transferring it to the Kindle via a USB cable or by emailing it to a registered email address provided by Amazon (for a fee via 3G, or free via Wi-Fi); the email service can convert a number of document formats to Amazon’s AZW format and then transmit the result to the associated Kindle over Whispernet. Amazon also has an application and browser extension called “Send to Kindle,” which users can use to convert a web page to a format that can be read on Kindle. In addition to published content, Kindle users can also access the Internet using the experimental web browser, which uses NetFront.
In late 2007, new releases and New York Times best sellers were being offered for approximately $11, with first chapters of many books offered as free samples. Many titles, including some classics, are offered free of charge or at a low price, which has been stated to relate to the cost of adapting the book to the Kindle format. Magazines, newspapers and blogs via RSS are provided by Amazon per a monthly subscription fee or a free trial period. Newspaper subscriptions cost from $1.99 to $27.99 per month; magazines charge between $1.25 and $10.99 per month, and blogs charge from $0.99 to $1.99 per month. Amazon e-book sales overtook print for one day for the first time on Christmas Day of 2009.
International users of Kindle pay different prices for books depending on their registered countries. For U.S. customers traveling abroad, Amazon originally charged a $1.99 fee to download books over 3G while overseas. That charge was quietly dropped in May 2010.
Fees remain for wireless delivery of periodical subscriptions and personal documents.
In addition to the Kindle store, paid content for the Kindle can be purchased from various independent sources such as Fictionwise, Mobipocket, and Baen Ebooks. Public domain titles are also obtainable for the Kindle via content providers such as Project Gutenberg, The Internet Archive, Retroread, and World Public Library. In 2011, the Kindle store had more than twice as much paid content as its nearest competitor, Barnes and Noble.
Public libraries that offer books via OverDrive, Inc. also loan titles for the Kindle and Kindle reading apps. Books are checked out from the library’s own site, which forwards to Amazon for the completion of the checkout process. Amazon then delivers the title to the Kindle for the duration of the loan, though some titles may require transfer via a USB connection to a computer. If the book is later checked out again or purchased, annotations and bookmarks are preserved.
The device is sold with electronic editions of its owner’s manual; the U.S. version also includes the New Oxford American Dictionary and the UK version, the Oxford Dictionary of English (not to be confused with the Oxford English Dictionary). Users can purchase different dictionaries from the Kindle store as specified in the included manual.
As a member of Amazon Prime, access to the “Kindle Owners’ Lending Library” is given that allows Kindle-owning members to borrow one free ebook, from over 500,000 titles, per calendar month. In July 2014, Amazon added a Kindle Unlimited subscription, which allows unlimited access to over 638,000 titles and 7,000 audiobooks for a monthly fee.
Operating system updates are designed to be received wirelessly and installed automatically during a period in sleep mode in which Wi-Fi is turned on. Kindles are charged using either a computer’s USB port or an AC adapter. The Kindle also contains experimental features such a basic web browser. Users can also play MP3 music in the background, if the device supports MP3 playback.
Kindle devices do not support the EPUB file format used by many other e-book readers. Instead, they are designed to use Amazon’s own e-book formats: AZW, and, in fourth generation and later Kindles, AZW3, also called KF8. Like EPUB, these formats are intended for reflowable, richly formatted e-book content and support DRM restrictions, but unlike EPUB, they are proprietary formats. Free software such as the free and open source calibre, Amazon’s KindleGen, and the email based Send-to-Kindle service are available to convert e-books into these formats. Kindle devices can also display some generic document formats such as plain text (TXT) and Portable Document Format (PDF) files, however reflowing is not supported for these file types. Instead text size may be increased or decreased on the screen by zooming, which means one has to scroll right to read the end of a line and back left to start reading the next line and so on. This may be avoided by converting the PDF file to MOBI format using calibre e-book management software.
The first Kindle devices used the AZW e-book format, which is identical to the Mobipocket (MOBI) format for files that are not DRM-restricted.
The Kindle Fire introduced the “Kindle Format 8” (KF8), better known as AZW3. AZW3 supports a subset of HTML5 and CSS3 features, while also acting as a container for a backwards-compatible MOBI content document.
The first-generation Kindle can read only unprotected Mobipocket files (MOBI, PRC), plain text files (TXT), Topaz format books (TPZ), and Amazon’s AZW format.
The Kindle 2 added native PDF capability with the version 2.3 firmware upgrade. Earlier versions could not generally read PDF files, but Amazon provided “experimental” conversion to the native AZW format, with the caveat that not all PDFs may format correctly. The Kindle 2 added the ability to play the Audible Enhanced (AAX) format, but dropped the ability to read Audible versions 2 and 3. The Kindle 2 can also display HTML files stored on the unit.
The fourth/fifth generation Kindles, Kindle Touch, and Kindle Paperwhite (1st and 2nd generation) can display AZW, AZW3, TXT, PDF, unprotected MOBI, and PRC files natively. HTML, DOC, DOCX, JPEG, GIF, PNG, and BMP are usable through conversion. The Touch and Touch 3G can also play Audible Enhanced (AA, AAX) and MP3 files. Amazon added in 2012 an update to the fourth generation Kindles to support the AZW3 format.
Amazon offers an email-based service that will convert GIF, PNG, and BMP graphics to AZW. Amazon will also convert HTML pages and Microsoft Word (DOC or DOCX) documents through the same email-based mechanism, which will send a Kindle-formatted file to the device via 3G for $0.15 per MB or via Wi-Fi for free. In addition, this service can send unprotected Mobi files to a user’s Kindle. These services can be accessed by Kindle devices, iOS devices running Kindle app version 2.9 or greater, and Android devices running Kindle app version 3.5 or greater.
A book may be downloaded from Amazon to several devices at the same time. The devices sharing the book must be registered to the same Amazon account. A sharing limit typically ranges from one to six devices, depending on an undisclosed number of licenses set by the book publisher. When a limit is reached, the user must remove the book from some device or unregister a device containing the book in order to add a book to another device.
The original Kindle and Kindle 2 did not allow the user to organize books into folders. The user could only select what type of content to display on the home screen and whether to organize by author, title, or download date. Kindle software version 2.5 (released July 2010) allowed for the organization of books into “Collections” which behave like non-structured tags/labels: a collection can not include other collections, and one book may be added to multiple collections. These collections are normally set and organized on the Kindle itself, one book at a time. The set of all collections of a first Kindle device can be imported to a second Kindle device that is connected to the cloud and is registered to the same user; as the result of this operation, the documents that are on the second device now become organized according to the first device’s collections. calibre had a plugin that made it possible to organize these collections on a computer, but this plugin no longer functions on newer models such as the Kindle Touch and Kindle Fire. There remains no option to organize by series or series order, as the AZW format does not possess the necessary metadata fields.
Users can bookmark, highlight, and search through content. Pages can be bookmarked for reference, and notes can be added to relevant content. While a book is open on the display, menu options allow users to search for synonyms and definitions from the built-in dictionary. The device also remembers the last page read for each book. Pages can be saved as a “clipping”, or a text file containing the text of the currently displayed page. All clippings are appended to a single file, which can be downloaded over a USB cable. Due to the TXT format of the clippings file, all formatting (such as bold, italics, bigger fonts for headlines, etc.) is stripped off the original text.
On July 18, 2011, Amazon began a program that allows college students to rent Kindle textbooks from three different publishers for a fixed period of time.
On January 21, 2010, Amazon announced the forthcoming release of its Kindle Development Kit. It aims to allow developers to build ‘active content’ for the Kindle, and a beta version was announced with a February 2010 release date. A number of companies have already experimented with delivering active content through the Kindle’s bundled browser, and the KDK promises ‘sample code, documentation and the Kindle Simulator’ together with a new revenue sharing model for developers.
The KDK is based on the Java programming language, specifically, the Personal Basis Profile 1.1.2 (JSR 217) flavor of packaged Java APIs.
As of March 2012 These items include simple applications and games, including a free set provided by Amazon Digital Services. As of 2012, the active content is only available in the US (or users with a US billing address).
Kindle store offers over 200 items labeled as active content.
Concurrently with the Kindle device, Amazon launched Kindle Direct Publishing, where authors and publishers independently publish their books directly to Kindle and Kindle Apps worldwide. In open beta testing as of late 2007, the platform has been promoted to established authors by an e-mail and by advertisements at Amazon.com. Authors can upload documents in several formats for delivery via Whispernet and charge between $0.99 and $200.00 per download. These documents may be written in 34 languages.
In a December 5, 2009 interview with The New York Times, CEO Jeff Bezos revealed that Amazon.com keeps 65% of the revenue from all ebook sales for the Kindle. The remaining 35% is split between the book author and publisher. After numerous commentators observed that Apple’s popular App Store offers 70% of royalties to the publisher, Amazon began a program that offers 70% royalties to Kindle publishers who agree to certain conditions. Some of these conditions, such as the inability to opt out of the lendability feature, have caused some controversy.
Other criticisms involve the business model behind Amazon’s implementation and distribution of e-books. Amazon introduced a software application allowing Kindle books to be read on an iPhone or iPod Touch. Amazon soon followed with an application called “Kindle for PCs” that can be run on a Windows PC. Due to the book publishers’ DRM policies, Amazon claims that there is no right of first sale with e-books. Amazon states they are licensed, not purchased; so unlike paper books, buyers do not actually own their e-books according to Amazon. This has, however, never been tested in court, and the outcome of any action by Amazon is uncertain. The law is in a state of flux in jurisdictions around the world.
Amazon has reported the Kindle version of Fifty Shades of Grey sold more than double that of Amazon’s print sales of the book, and, in June 2012, the Kindle edition became the first to sell more than one million copies.
Blogs published by popular media outlets such as TechCrunch and Ars Technica have been available on Kindle as early as 2008. In May 2009, the program was opened to everyone.
Amazon, not the publisher, sets the monthly subscription rate for each blog between $0.99 – $1.99. Since the blogs may contain pictures, and wireless 3G access requires no monthly subscription fee, Amazon retains 70% of the revenue from blog sales, remitting 30% to the content publisher.
As of July 2014, the program status is listed as beta.
Kindle devices may report information about their users’ reading habits “such as up-time [and] last page read” to Amazon. The exact data collected and sent is unclear, though.
On July 17, 2009, Amazon.com withdrew certain Kindle titles, Animal Farm and Nineteen Eighty-Four by George Orwell, from sale, refunded the cost to those who had purchased them, and remotely deleted these titles from purchasers’ devices after discovering that the publisher lacked rights to publish the titles in question. Notes and annotations for the books made by users on their devices were left in a separate file, but “rendered useless” without the content to which they were directly linked. The move prompted outcry and comparisons to Nineteen Eighty-Four itself. In the novel, books, magazines and newspapers in public archives that contradict the ruling party are either edited long after being published or destroyed outright; the removed materials go “down the memory hole”, the nickname for an incinerator chute. Customers and commentators noted the resemblance to the censorship in the novel, and described Amazon’s action in Orwellian terms. Some critics also argued that the deletion violated the Kindle’s Terms of Service, which states in part:
Upon your payment of the applicable fees set by Amazon, Amazon grants you the non-exclusive right to keep a permanent copy of the applicable Digital Content and to view, use and display such Digital Content an unlimited number of times, solely on the Device or as authorized by Amazon as part of the Service and solely for your personal, non-commercial use.
Amazon spokesman Drew Herdener stated that the company is “… changing our systems so that in the future we will not remove books from customers’ devices in these circumstances.” On July 23, 2009, Amazon CEO Jeff Bezos posted an apology about the company’s handling of the matter on Amazon’s official Kindle forum. Bezos said the action was “stupid”, and that the executives at Amazon “deserve the criticism received.”
On July 30, 2009, Justin Gawronski, a Michigan high school senior, and Antoine Bruguier, a California engineer, filed suit against Amazon in the United States District Court for the Western District of Washington. Gawronski argued that Amazon had violated its terms of service by remotely deleting the copy of Nineteen Eighty-Four he had purchased, in the process preventing him from accessing annotations he had written. Bruguier also had his copy deleted without his consent, and found Amazon practiced “deceit” in an email exchange. The complaint, which requested class-action status, asked for both monetary and injunctive relief. The case was settled on September 25, 2009, with Amazon agreeing to pay $150,000 divided between the two plaintiffs, on the understanding that the law firm representing them, Kamber Edelson LLC, “…will donate its portion of that fee to a charitable organization…”. The settlement also saw Amazon guaranteeing wider rights to Kindle owners over its e-books:
For copies of Works purchased pursuant to TOS granting “the non-exclusive right to keep a permanent copy” of each purchased Work and to “view, use and display [such Works] an unlimited number of times, solely on the [Devices]… and solely for [the purchasers’] personal, non-commercial use”, Amazon will not remotely delete or modify such Works from Devices purchased and being used in the United States unless (a) the user consents to such deletion or modification; (b) the user requests a refund for the Work or otherwise fails to pay for the Work (e.g., if a credit or debit card issuer declines to remit payment); (c) a judicial or regulatory order requires such deletion or modification; or (d) deletion or modification is reasonably necessary to protect the consumer or the operation of a Device or network through which the Device communicates (e.g., to remove harmful code embedded within a copy of a Work downloaded to a Device).
On September 4, 2009, Amazon offered affected users a restoration of the deleted e-books, an Amazon gift certificate, or a check for the amount of $30.
In December 2010, three e-books by author Selena Kitt were removed due to violations of Amazon’s publishing guidelines. For what Amazon describes as “a brief period of time,” the books were unavailable for redownload by users who had already purchased them. This ability was restored after it was brought to Amazon’s attention; however, no remote deletion took place.
In October 2012, Amazon deleted every book that Linn Nygaard, an IT consultant living in Norway, had purchased, and canceled her Amazon account. Amazon claimed that she had violated their terms of service, but was not specific as to what she had done wrong. The next day Amazon restored her account and books.