Wrap You Head Around These Number, Will You?: Amazon's e-Books Outsell Paperbacks

Last week, Amazon announced that its goal of selling more e-books than paperbacks has come early, based on fourth-quarter earning statements from 2010. According to this ComputerWorld report, Amazon reports that in 2010, it sold 15% more e-books than paperbacks, and 3 times as many e-books as hardcovers. As for Kindles themselves, we only know that Amazon has sold "millions," making it the single bestselling product in Amazon history. But no solid numbers have been released.

What I can't wrap my head around is the fact that in the very same article, analyst Allan Weiner is cited as claiming that e-books still make up only 10% of overall book sales. But if e-books are selling more than paperbacks or hardcovers on Amazon, and no one is buying books from Borders (it is out of money, after all), and the independents are struggling to keep up with Amazon... well, where are we buying those 90% paper books?

Furthermore, we know that e-books sold on Amazon are only compatible with the Kindle(s) or with a Kindle app on an Android device, iPod, iPhone or iPad. Can you read Amazon books on a Kobo? Or a Sony Reader? I don't think you can, but if anyone thinks different, please let me know. I'd be interested to know the statistics for where non-Kindle readers buy their e-books.

Note that none of the Amazon figures include free e-books, of which there are plenty.

So, does anyone have any further insight here? If Amazon's e-books are outselling their paperback or hardcover companions, but e-books are still only 10% of the market, I just have a hard time making the logic work. Maybe I'm missing something, or maybe this is just why I wasn't destined to study economics. Thoughts?