The main thrust of the book is intended for retailers who wish to increase their sales. Underhill runs a consulting business with some big-name clients and he helps them figure out how to sell more stuff. I found many of the case studies interesting, even amusing. He talks about the problem of "butt-bump" in which retail sales racks are placed too close together and people get jostled as they look at the merchandise. People don't like that. Some things should be obvious, but he addresses practicalities such as the fact that shoppers have only two hands and the retailer has to provide a place for shoppers to set things down when necessary.
After the novelty wore off, I found the book pretty boring. Underhill's whole focus is how retailers can make it easy for people to buy more stuff. It was written in 1999, so the chapter on internet sales was woefully out of date. I gave up on the book before I finished it. I hesitate writing a negative review, but sometimes it's nice to cross off a book instead of add it to a list of books to be read. I'd give this book 1 out of 5 stars unless you own a retail store, in which case you just might want to read it!