Somewhat akin to this thread I highly recommend a book entitled, Why We Buy: The Science Of Shopping by Paco Underhill. The author calls himself a "retail anthropologist" and discusses his many years of just observing shoppers behavior in stores and malls, on behalf of large retailers.

He analyzes seemingly mundane behavior such as why shoppers tend to turn right when the enter a store, and that placing displays in obvious plain sight too close to a store entrance is a complete waste of space. What does this book say about Loyalty Programs, essentially nothing. However it is fascinating and an amusing read nonetheless, and this thread gave me an opening to bring it up .