Google will allow its "Book Search" partners in the United States and U.K. to sell online access to their books. In a March 10 e-mail, Google pitched the idea as a way for publishers to "earn more from your books." Since selling online access to books might cannibalize sales of the paper bound copies, Google seems to be arguing that it can provide more impulse purchases. Publishers can choose which books they want to offer.
See: http://www.weberbooks.com/publish.htm and http://books.google.com/support/partner/bin/answer.py?answer=34596