This article from the CHE documents some of the problems with Google Books:
There are bound to be occasional howlers in a corpus as extensive as Google’s book search, but these errors are endemic. A search on "Internet" in books published before 1950 produces 527 results; "Medicare" for the same period gets almost 1,600. Or you can simply enter the names of famous writers or public figures and restrict your search to works published before the year of their birth. "Charles Dickens" turns up 182 results for publications before 1812, the vast majority of them referring to the writer. The same type of search turns up 81 hits for Rudyard Kipling, 115 for Greta Garbo, 325 for Woody Allen, and 29 for Barack Obama. (Or maybe that was another Barack Obama.)
Certainly Google has undertaken an ambitious project. I have found Google Books to be a very helpful source of information in my scholarly research. Many of the books that I need are from smaller publishers and tend to be expensive, and I may only need one or two articles or bits of information. Rather than making a long trek to the (not-so-)local seminary libraries that may have a book that may not turn out to be helpful, I can see most or all of the book online.
And, as I have discovered with free music downloads, a free e-copy of the book makes me more likely to purchase a hard copy. I hope that more and more publishers will make their copyrighted works accessible for free with the goal of increasing readership and eventually sales. Books have been around for a long time, and they’re not going away.
What do you think about Google Books, and e-reading in general? Is it helpful to scholarly research, or does it breed error and laziness?