Amazon may not disclose how many Kindles the company has sold (using just the vague term "millions" in its latest earnings report), but the company has no problem playing up sales of ebooks to users of the Kindle platform. The company noted that it has sold three ebooks for every hardcover title and that ebooks are even outselling paperbacks (Amazon notes that it sells 115 ebooks to every 100 paperbacks).
The news isn't a complete surprise. Barnes and Noble noted last month that sales of ebooks on its Nook platform had similarly outpaced sales of physical books from its online store.
There are obvious advantages to ebooks, one of which is convenience. Another, perhaps more telling advantage is that electronic editions tend to cost noticeably less than their physical counterparts, particularly when it comes to recent hardcover releases. Amazon even noted this in its financial results release saying that more the 670,000 of the store's 810,000 plus books cost less than $9.99.
One reason that Amazon may be enjoying this level of success and yet be unwilling to disclose how many actual devices it has sold is that many of those ebook sales may not be tied to actual Kindle devices. As with Barnes and Noble's Nook, Amazon produces a range of Kindle apps that can be installed on smartphones (a Windows Phone 7 app recently joined apps for the iPhone, Android, and BlackBerry), tablets (including the iPad and Android tablets), PCs, and Macs. Amazon has also announced plan to follow Google's ebook-in-a-browser concept that would allow reading on any Internet-connected device.
By making the Kindle a platform that can be run on just about anything (and that syncs ebooks, last read locations, notes, and highlights across multiple devices), Amazon has positioned itself to rake in ebook sales even if it can't move Kindle hardware in vast quantities. Having the biggest ebook selection in the U.S. doesn't hurt either. Many tablet and smartphone users, myself included, may prefer to buy ebooks from other sellers (particularly if they're less expensive – something that Leatherbound.me can help you find out), but are willing to purchase from Amazon if that's the only source for a given title or if there's a notable price difference.
I prefer Apple's iBooks app on my iPad, for example. It has better highlight and notation features, has more options for organizing collections of books, doesn't require using an external browser to search for and purchase books, syncs titles automatically to iTunes rather than relying on access to Amazon's servers, and it just has a more book-like feel to it. That said, there are several books that I've been reading using the Kindle app simply because Amazon was the only source for electronic versions.
Whether Amazon can maintain that advantage in the long term is a big question. Apple's iBookstore and Barnes and Noble's Nook store have gained some ground (Barnes and Noble also offers apps for multiple platforms) and Google has recently tossed its hat into the ring. While their catalogs may not be as big as Amazon's, they are growing. They may also have an eventual advantage in their use of open standards in the form of EPUB as opposed to Amazon's proprietary standard for ebooks. For now, at least, Amazon definitely seems to be holding on to some of its advantages.