The blurb on their site says:
"Would you be surprised to learn that Google employs a stable of freelance researchers who answer questions for a fee? Google Answers has been around for several years now, but relatively few Internet users ever plow deep enough into Google's ever-expanding set of features to encounter it.
"Google Answers is designed fill the void when the search engine fails you. Users post questions, something like "Who will be required to pay the Alternative Minimum Tax in 2007" and specify how much you'll pay for an answer. A low bid means your question probably won't get answered. But if your fee is acceptable, a researcher will find the information you want, post it to Google Answers, and send you an email."
Jon Gordon interviewed Sarah Milstein, one of the authors of Google: The Missing Manual, 2nd edition. Too bad he didn't also have a librarian, who could talk about how librarians do the same thing -- for free.