Original concepts obtained from a query may be augmented with additional concepts connected to the original concepts in a concept graph in response to determining that the original concepts did not match a sufficient number of bid functions. The augmented set of concepts may then be evaluated with respect to the bid functions to identify matching ad functions. This process may be repeated until a sufficient number of matching ad functions are found. A bid amount of the matching bid functions may be calculated, such as based on semantic information obtained as a result of the query. The bid amounts may further be based on environmental information. A bid function is selected based on the bid amounts and the content associated with the bid function is provided to the source of the query. The content may be selected based on the semantic information.