Methods, systems, and apparatus, including computer programs encoded on a computer-readable storage medium, for evaluating a creative. Methods can include identifying one or more selection keywords that are associated with a creative. Matching criteria can be identified for comparing the selection keywords and the request keywords. The matching criteria can be defined by a range from an exact match to a broad match and include a matching threshold in the range. A bid modifier associated with the matching criteria can be established. The bid modifier can modify a bid associated with the creative based on an extent of a match determined between the selection keywords and the request keywords for a given content request. The creative responsive to received content requests can be evaluated based on the matching criteria and the bid modifier.