Now they announced that sale of Kindle titles are selling more than paperbacks as well.

During the Amazon’s announcement of their earning on Thursday, they notice that since January 1, U.S. customers have bought 115 Kindle editions for every 100 paperbacks sold. Hardbacks are outsold by Kindle titles by three-to-one margin.

Amazon even note that they did not count free Kindle volumes, but they counted even hardcover and paperbacks, which had no Kindle editions into statistics.

About 810.000 Kindle e-books are currently available on Amazon, versus 630.000 volumes last July. More than 670.000 Kindle books are sold for $9.99 or less, and many of the e-books on the New York Times bestseller list are priced closed to the $15 mark.