A method and system for inserting television commercials that are selected according to the unique interests and purchasing habits of viewers in individual households, or the relative location of the household within a local broadcast area. The present system provides a cable or satellite television set top box that stores a plurality of television commercials for products or services that have been found to be of interest to viewers in a household that uses the set top box. At commercial breaks during the broadcast of network television programs, the television network indicates when the set top box is authorized to insert a stored television commercial instead of a broadcast commercial. If the set top box locates a locally stored commercial that is appropriate for the television program and the user, the commercial is inserted into the commercial break.