The first part is the science of shopping. The second part considers the mechanics of shopping: how people physically react to the layout of space, other people in the store, etc. The third part deals with the demographics of purchasing: the different behaviors of men, women, seniors, and kids. The fourth section of the book tackles the dynamics of shopping: in other words how shoppers respond psychologically to the placement of merchandise, packaging, and other features of the merchandise itself.
The first part provides details on how Underhill and his trackers got started in the people-shopping business and why he got started in that business. There studies prove that the longer a shopper remains in a store, the more he or she will buy. In the part, the author points out the many things about shopping that retailer do not know: In some stores, buyers spend three to four times longer than non-buyers, get them to shop longer - talking to employees helps, and we can determine where shoppers will walk in a store.
The second part, the mechanics of shopping which I think are very practical and interesting for shopper. The "butt brush" effect - if aisles are too narrow or crowded, and shoppers have to bend over to reach merchandise, they are exposed to being brushed or touched by other shoppers as they pass by - this is a definite turn-off to shoppers (especially women), and will reduce the amount of time spent in the store and thus the total amount of money spent. Shoppers need the use of their hands to touch, feel, pick up and examine merchandise - if they are burdened down with a coat, several other items that they have picked up, a toddler, etc., they will spend less time in the store than if they had a shopping cart, access to a coat check, strollers, baskets (placed inside the sore interior where they could actually be useful to someone who has already accumulated a few items) .