There's no denying that e-books are already big business, and market research firm Forrester is now offering some pretty impressive numbers that show just how big it already is, and how much bigger it will get in the next few years. The firm surveyed some 4,000 people and found that while just seven percent of those actually read e-books, they still bought enough of them to translate to $966 million in sales this year -- a number that's projected to grow to $3 billion by 2015. As for the reading habits of that seven percent, Forrester found that they "read t
