A cable television distribution system in which the head end substitutes different channels for a plurality of separated geographic zones. The head end creates a plurality of channel spectrums and transmits the spectrums on distribution trunks such that a different spectrum may be present on each distribution trunk. The spectrums on the distribution trunks are connected to zones of the viewer community which have been selected for market research purposes on the basis of demographics. Product sales collection units are provided at stores throughout the community served by the cable television distribution to collect consumer purchase data for market research purposes.