9. One or more computer-readable media having computer-executable instructions embodied thereon that, when executed, facilitate a method of determining that a query is relevant to a category of information, the method comprising associating a seed document with the category, wherein the seed document is trusted to be relevant to the category; receiving an identification of a query that was previously input to a search engine, wherein, when a search-result document was presented in response to the query, the search-result document was selected; determining that the search-result document matches the seed document; based on the search-result document matching the seed document, deeming the query to be relevant to the category; receiving a request to provide a keyword that is relevant to the category; and providing the query as the keyword that is relevant to the category.
10. The one or more computer-readable media of claim 9 , wherein the seed document contains content that describes the category, which an entity desires to have its message displayed in conjunction with.