My understanding is that cable tv early on was called CATV (Community Antenna Television) and was used in places where the local topography made television rece

My understanding is that cable tv early on was called CATV (Community Antenna Television) and was used in places where the local topography made television reception difficult so the community came together to have one high quality antenna in a good location for reception and then distributed that signal to members of the community who helped cover the costs. In that case, advertising would have been whatever already was being broadcast to the antenna.