Leather-bound books and rich mahogany shelves may soon be as endangered as the 70's playboy who used them to impress women.
Today, Amazon announced that sales of books for its popular Kindle reading device are far outpacing sales of hardcover books. The online retailer said  that it's sold 143 Kindle e-books for every 100 hardcover books over the past three month. In the last four weeks, that figure has jumped to 180 e-books per every 100 hardcovers.
"Even while our hardcover sales continue to grow, the Kindle format has now overtaken the hardcover format," says Amazon founder and CEO Jeff Bezos. "[It's] astonishing when you consider that we've been selling hardcover books for 15 years, and Kindle books for 33 months."
These numbers come at a good time for Amazon, whose Kindle is facing increased competition from other e-readers and widening belief that the iPad and other tablets could end its market control. Last week, analysts at Credit Suisse  estimated that Amazon's share of e-book sales would fall from 90% to 35% in the next five years.
For now, however, it seems the Kindle is keeping up with its rivals. E-book sales have leaped more than 207% according to a report by the Association of American Publishers, but Amazon said today it has exceeded that growth rate, having tripled the Kindle's book sales in the first half of 2010.
Amazon's e-book market success is aided by a recent price drop of the Kindle, from $259 to $189, which Bezos said has helped spur significant sales for the device. Vast, important library and the impression that you're incredibly well-read sold separately.