Smartphone signals for retail analytics

Shopping online offers customers convenience and price transparency, but it offers retailers even more. As Amazon has demonstrated in its successful model, the information it derives from its customer behavior online gives it insight that it uses to tailor its marketing to the individual. As your online browsing tracks, not only what you buy, but what you considered buying, the retailer gets to learn a lot more about you than the person who rings up your purchase at a store. How can a bricks-and-mortar establishment compete with that kind of analytic edge?