There is an interesting book written about this. It is "Why We Buy: The Science of Shopping" by Paco Underhill. From the editorial review: In an effort to determine why people buy, Paco Underhill and his detailed-oriented band of retail researchers have camped out in stores over the course of 20 years, dedicating their lives to the "science of shopping." Armed with an array of video equipment, store maps, and customer-profile sheets, Underhill and his consulting firm, Envirosell, have observed over 900 aspects of interaction between shopper and store. They've discovered that men who take jeans into fitting rooms are more likely to buy than females (65 percent vs. 25 percent). They've learned how the "butt-brush factor" (bumped from behind, shoppers become irritated and move elsewhere) makes women avoid narrow aisles. They've quantified the importance of shopping baskets; contact between employees and shoppers; the "transition zone" (the area just inside the store's entrance); and "circulation patterns" (how shoppers move throughout a store). And they've explored the relationship between a customer's amenability and profitability, learning how good stores capitalize on a shopper's unspoken inclinations and desires.
Underhill, whose clients include McDonald's, Starbucks, Estée Lauder, and Blockbuster, stocks Why We Buy with a wealth of retail insights, showing how men are beginning to shop like women, and how women have changed the way supermarkets are laid out. He also looks to the future, projecting massive retail opportunities with an aging baby-boom population and predicting how online retailing will affect shopping malls. This lighthearted look at shopping is highly recommended to anyone who buys or sells.