It's well off the triple year-over-year growth that e-books saw a few years ago, but the latest report from the Association of American Publishers shows that e-books did inch up even further in 2012 to account for a sizeable chunk of overall book sales. According to its figures, e-books now represent 22.55 percent of US publishers' total revenue -- up from just under 17 percent in 2011 -- an increase that helped push net revenue from all book sales up 6.2 percent to $7.1 billion for th
