Kindle reads the electronic document in Amazon‘s AZW proprietary format file (KF8 for the last files), it supports TXT format and MP3 audio format and audio book format but from the company Audible.com, but not EPUB format supported by many other e-readers. Kindle also supports JPEG, GIF, PNG and BMP file type. Word and DOC documents need to be sent to Amazon so that it performs the conversion to AZW format. Since version 2.3 of the Kindle softwar it allows native reading of PDF format.
International newspapers (including The New York Times, Frankfurter Allgemeine and The World), magazines and a blog catalog is available as a subscription. The Kindle also read free content of Wikipedia and New Oxford American Dictionary.
The press emphasizes the simplicity with which it will make purchases and noted that the Kindle uses the concept of digital books with an innovative business model, in fact “the costs of connection [to the Sprint network] are included in the price of the content”, but regrets that access to the blog catalog is paying. It also criticized the Kindle non-support for many text formats such as PDF, unlike its competitor the Sony Reader and its proprietary format. Indeed, the content downloaded to the Kindle from Amazon.com can not be played on devices of other manufacturers.
Amazon is offering a complimentary service to convert Microsoft Word, TXT, HTML, PDF, or image files in JPEG or GIF formats. Just send files by e-mail on their servers and receive by return compatible file by email. A financial contribution is required if the user wants to receive the converted file directly on their device via the 3G network.