destinyland writes: The Association of American Publishers revealed today that e-book sales have doubled in the last year. Sixteen publishers reported that in February e-book sales totaled more than $90.3 million, a 202.3% increase over e-book sales in February of 2010. Meanwhile, sales of adult hardcover books have dropped 43%, while mass-market paperback sales dropped 41.5% (earning just $46.2 million and $29.3 million, respectively). The book publishing association acknowledged that readers have "made e-books permanent additions to their lifestyle," arguing that publishers "are constantly redefining the timeless concept of 'books'" and identifying new audiences they can serve through emerging technologies. "It's nice to see that book publishers are aware of the changes rocking their industry," notes one e-book blog, "and that they're approaching it with a sense of history."