amazon kindle 260x228 Amazon eBooks starting to blow the cover off of hardcover salesOver the last three months, Amazon has sold more eBooks than hardcovers through its Kindle service (i.e. not just being read on the Kindle device, but across devices).

While paperbacks are still probably outselling eBooks (Amazon did not specify this) as Jeff Bezos was quoted as saying, “astonishing when you consider that we’ve been selling hardcover books for 15 years, and Kindle books for 33 months.”

143 eBooks were sold for every 100 hardcover books over the last 90 days, and in the last month alone, that number has risen to 180 eBooks for every 100 hardcover books. Also detailed in the press release:

  • Amazon sold more than 3x as many Kindle books in the first half of 2010 as in the first half of 2009.
  • On July 6, Hachette announced that James Patterson had sold 1.14 million e-books to date. Of those, 867,881 were Kindle books.
  • Five authors–Charlaine Harris, Stieg Larsson, Stephenie Meyer, James Patterson, and Nora Roberts–have each sold more than 500,000 Kindle books.

Of course, hardcovers still generally cost more than eBooks, so overall revenue may still be higher from hardcover books, but volume should quickly overcome the price difference if it continues on this path. Pretty astonishing stuff indeed.

Certainly one of the major drivers over the last 90 days has been the introduction of the iPad (and Kindle for iPad) as well as the Kindle app for Android, not to mention the lower price of the Kindle itself. Amazon can’t be the only one that is happy to hear this news, as nearly all of the major booksellers at this point are firmly in the eBook game, as well as Apple and soon Google. To Amazon’s competitor’s ears, this is certainly an announcement that they will interpret as “a rising tide lifts all boats,” but is it, or is Amazon continuing to build a bigger lead?

Think about the numbers here for a second and think how many hardcover books that Amazon probably sells in a month. Now consider that if this trend continues as Amazon is reporting, eBook sales (by number) will almost certainly be at least double that of hardcovers – with Amazon’s scale already, that’s going to be a very large number, and Amazon may just be widening a gap that it had firm control over for over for nearly two years.

As our Alex Wilhelm pointed out last month, Amazon is obviously still killing it.

(Note: Sales numbers do not include free downloads of Amazon’s 1.8 million out-of-copyright downloadable books.)