Amid e-book price war, Kindle books skyrocket, outsell hardcover

In the midst of a Summertime e-reader price war, initiated by Borders, matched by Barnes and Noble, and escalated by Amazon, e-books are flying off of their virtual shelves.

Today, Amazon founder and CEO Jeff Bezos announced second quarter Kindle sales are fully accelerated, with each month outselling the last. But since cutting the price in June, sales have massively spiked.

"We've reached a tipping point with the new price of Kindle--the growth rate of Kindle device unit sales has tripled since we lowered the price from $259 to $189," said Bezos. "In addition, even while our hardcover sales continue to grow, the Kindle format has now overtaken the hardcover format. Amazon.com customers now purchase more Kindle books than hardcover books--astonishing when you consider that we've been selling hardcover books for 15 years, and Kindle books for 33 months."

Amazon has sold 143 Kindle books for every 100 hardcover books it has sold. This is not quite a two-to-one ratio, but it's very close, amounting to roughly 1.7 : 1. This includes versions of books where there isn't even a Kindle version, and excludes free Kindle titles. If Amazon stacked the numbers differently, the ratio could be even greater.

So what are people reading on their Kindles? Amazon today said Charlaine Harris, Stieg Larsson, Stephenie Meyer, James Patterson, and Nora Roberts have each sold more than 500,000 Kindle books, and James Patterson is leading the pack with 867,881.