Google Answers lets you post a question that you want answered by any one of Google’s 500 screened researchers. You specify a price that you are willing to pay for the information, starting at $2.50. Once your question is answered it is added to the database so that others can browse or search it for free. You can also rate the response.
The service never took off. People just don’t want to pay for information. (Which is why membership libraries such as Jenkins have to beg for members.)