Mr. Gimein is right. Not only does Google not rip off authors & publishers, it increases the possibility that books will be purchased by helping bring those books to potential readers attention. It is a great help to scholars and librarians.
Anyone who has attempted to read a Google book online (you can't print most of them) knows that it discourages lengthy reading & encourages purchasing the book or finding it in a library, actions which Google makes easy from their Google Books pages.