An ArcView GIS application was developed for a major national broadcasting company. It superimposes and compares the three layers below and highlights television signal invasion throughout the original contracted areas. 1. The potential market in each municipality 2. The contractual signal area 3. The covered signal area ArcView GIS resources allow the advertising market (research institutes, advertising agencies, and announcers) to figure precisely the target public of each covered signal area, show all the relevant sites where the broadcast signals have to be improved, and convince the engineering department to change its optic system and join technical solutions to the marketing view.