Ebooks by the numbers.(Internet Waves)

When the news crossed the media's radar screen this summer, it was the publishing industry equivalent of "the shot heard 'round the world." For the first time ever, Amazon.com reported it had sold more ebooks in the previous 3 months than hardcover dead-tree books. And not by just a slim margin either. The company said that for every 100 hardcover books, it sold 143 Kindle editions.

Amazon CEO Jeff Bezos remarked that this was "astonishing when you consider that we've been selling hardcover books for 15 years, and Kindle books for 33 months."

Ebook Sales Soaring

Digging further into the numbers divulged in Amazon's press release, which is always interesting since the company is notoriously secretive when it comes to sales figures, here are some other compelling tidbits:

* Over the previous month (June 2010), Amazon sold 180 Kindle editions for every hardcover.

* The company sold more than three …