Alan P. Kuritsky, AT&T John D.C Little, MIT Alvin J. Silk, MIT Emily Bassman, MIT AT&T developed a new marketing strategy for its residential long distance market place.  The five year program of market segmentation, ad copy testing and a new ad campaign was tested in a large field experiment. The experiment showed that ad copy changed purchase behavior and that the AT&T should see an additional $100million by implementing the new ad campaign.