One or more keywords and/or information about one or more properties may be accepted, and a set of one or more taxonomy categories may be determined using at least some of the keyword(s) and/or property information. Each of the taxonomy categories may be a vertical category, and at least one of the set of one or more determined taxonomy categories may be presented to an advertising user as an ad targeting suggestion. Each of the taxonomy categories may have at least one property (e.g., Web document), that participates in an advertising network, associated with it. An advertiser selection of a suggested taxonomy category may be accepted, the serving of an ad of the advertiser may be targeted to each of the at least one property (e.g., Web document) associated with the selected suggested taxonomy category. An offer for association with the selected suggested taxonomy category may be provided by the advertiser. A set of one or more properties (e.g., Web documents) may be determined using at least some of the determined one or more taxonomy categories. Such properties (perhaps along with viewing information) may be presented to an advertising user as an ad targeting suggestion. A suggested property (e.g., Web document) may be selected by a user. If so, the serving of an ad of the advertiser may be targeted to the selected suggested property. An offer for association with the selected suggested document may be accepted from the advertiser. The set of one or more taxonomy categories may be performed by determining a set of one or more semantic clusters (e.g., term co-occurrence clusters) using the accepted keyword(s) and/or property information, and determining a set of one or more taxonomy categories using at least some of the one or more semantic clusters.