Wired: "E-books have hit the mainstream, and for the first time are consistently outselling their pulp-and-ink brethren, according to Amazon.com.
Amazon hit a symbolic milestone last holiday season, when for one day its sales of e-books exceeded the number of dead-tree books it had sold.
Now the company has hit a more significant milestone, selling 143 e-books for every 100 hardcover books sold over the course of the second quarter. The rate is accelerating: For the past month, Amazon sold 180 e-books for every 100 hardcovers, and it sold three times as many e-books in the first six months of this year as it did in the first half of 2009.
Amazon’s Kindle bookstore now offers more than 630,000 books, Amazon says, plus 1.8 million free, out-of-copyright titles."