12. A computer-implemented method comprising: a) receiving, with an advertising system including at least one computer, relevance information for an advertisement; b) determining, with the advertising system, at least one audio document using the received relevance information; c) generating, with the advertising system, information about the at least one audio document for presentation to an advertiser associated with the advertisement; and d) receiving, with the advertising system, from the advertiser, an offer to have its advertisement served with the at least one audio document accepted by the advertiser.
12. A computer-implemented method comprising: a) receiving, with an advertising system including at least one computer, relevance information for an advertisement; b) determining, with the advertising system, at least one audio document using the received relevance information; c) generating, with the advertising system, information about the at least one audio document for presentation to an advertiser associated with the advertisement; and d) receiving, with the advertising system, from the advertiser, an offer to have its advertisement served with the at least one audio document accepted by the advertiser. 25. The computer-implemented method of claim 12 wherein the relevance information received was determined by analyzing information associated with the advertisement.