System and method for identifying advertising opportunities

This specification describes technologies relating to content presentation. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of processing quantities of query instances to calculate (a) a volume differential between the quantities, (b) a percentage differential between the quantities, and (c) a volume differential between the impressions per query instance values, computing a first opportunity index that includes a product of: (a) an absolute value of the volume differential between the quantities, and (b) the percentage differential between the quantities, computing a second opportunity index including a product of: an absolute value of the first opportunity index, the volume differential between the impressions per query instance values, and the impressions per query instance values, and providing campaign improvement suggestions to an advertiser based on the second opportunity index. Other embodiments include corresponding systems, apparatus, and computer program products.