“'You can’t just make a book anymore,' said Mr. Haarsma, a former advertising consultant. Pairing a video game with a novel for young readers, he added, 'brings the book into their world, as opposed to going the other way around.'”
Read more at:
http://www.nytimes.com/2008/10/06/books/06games.html?_r=1&hp&oref=slogin