Systems, methods, and computer program products identify one or more web page impressions satisfying one or more simply queries, each of the one or more web page impressions associated with a respective impression ID. Respective impression IDs of the one or more web pages satisfying the one or more simple queries are stored in an impression log. Subsequent to storing the respective impression IDs, a query is received from a client device, and a number of impression IDs for the one or more web pages satisfying the query are identified based on the identified one or more web page impressions satisfying the one or more simple queries.