Laura Hazard Owen, PaidContent:

Ebooks accounted for 22.55 percent, or nearly a quarter, of U.S. book publishers’ sales in 2012, according to a full-year report released by the Association of American Publishers Thursday. That’s up from 17 percent of sales in 2011 and 3 percent in 2009. Ebook growth continued to plateau, however, suggesting that the industry is maturing.

The U.S. trade book industry saw $7.1 billion in revenue in 2012, with $1.54 billion coming from ebooks.