1. A method comprising: defining at least one category as containing documents that may be retrieved; associating at least one supercategory with multiple categories including said at least one category by mapping the multiple categories to the at least one supercategory; associating an advertisement with at least one of said supercategories, the advertisement being separate from the documents contained in the at least one category; determining at least one term associated with a user search query; determining by a computer a first of said at least one supercategory based on at least one term of said user search query and said multiple categories of the at least one supercategory; forming a banner ad term list, each element in said banner ad term list including terms of said first supercategory and terms of said at least one category associated with said first supercategory; and displaying an advertisement associated with said first supercategory, wherein said documents include business information taken from listings in at least one directory of businesses.