Why We Buy


Why We Buy is a consumer psychology book written by Paco Underhill, a consultant who uses consumer psychology to help increase the sales of various retail stores.

The book is intended as an overview of the work he has done throughout his years of consultation and answer the fundamental question of “why we buy”.

The Retail Environment

The first two chapters, the author establishes a useful analogy between anthropology and retail sciences. That is, similar to how anthropologists take interest to humans who live within different environments, so as to study the human within a different context, so too do retail scientists investigate the human within the retail environment.

How do we behave when stores are jam packed? Do we buy more of something when it is placed on one side of the store rather than the other side? How is it we scan the surface of products, and how much information do we actually extract from glancing at products?

It becomes clear that the book is going to unfold and characterize the human variable with the retail economy. All of the principles to be grasped shall pertain mostly to humans within the retail context.

The Entrance

In chapter three, the author begins to discuss the importance of the events which come first when we shop: the entry into the store. When we walk from the parking lot to the store, we get a cardio-vascular workout; only because everyone speedily walks through the parking lot, since the parking lot is seldom where anyone wants to be for long.

This increase in heart-rate has an impact upon how we enter the store; we enter walking fast, but we eventually slow down after a few seconds inside the store. However, because we are going fast, and because we are adjusting to the new lighting, sounds, and temperature, we ignore plenty of the information within the front of the store.

The author labels the entry the “decompression zone,” and believes this zone should never contain important information, as consumers will always ignore or fail to see it. One of the solutions, the author says, to the problem of slowing down the customers is the “discount items”. A good way to slow down customers is to introduce heavily discounted items within the entrance.

The Hands

In reliable fashion, the book continues to bring to the forefront the obvious and provide non-obvious insights about consumerism. In chapter four, we talk about the hands of consumers.

Consumers usually walk around with phones, bags, or coffee; seldom can we find a consumer who has both hands free. And when their hands are free, they’ll soon be filled with products. And if their hands are full of products, then they can no longer shop.

In one study, the author advised a drug department store to train their employees to offer customers baskets, if and only if they had three or more items in their hands. Doing so lead to an increase in sales!

As well, the author talks about the importance of placement for baskets. Baskets placed at the entrance never get used. But when baskets are distributed throughout the store, everyone grabs them mid-shopping. He also mentions the importance of basket design, and how customers don’t want to be caught walking around with a flimsy basket that impacts their social status negatively. The baskets have to be enticing.

Again and again, the author mentions how he increases sales by utilizing basket placement, design, and freeing-up the consumers hands. Obvious but important points.

The Signs

Chapter five discusses the importance of signs: where to place them, bad habits to avoid, and examples of good and bad sign systems.

The author discusses how it is people actually read signs. For example, in some stores, the average person spent no more than 2.9 seconds reading signs that were located near the entrance. He likewise talks about the importance of considering the mental state of the person who is about to read the sign: are they preoccupied? Good placement can make or break a signs ability to perform.

How People Move

How people move inside a store can actually have an impact on the sales of products. For example, in North America, most customers slowly drift to the right of the store upon entrance. Therefore, the products placed inside the right side of the store are the products which gain access to fresh, cognitively alert consumers.

The movement habits of consumers can therefore be used to increase the sales of certain products; their movement effectively makes certain areas within the store high-price real-estate.

In addition, when we consider how people walk, it becomes apparent that people walking seldom look below their knees or above their shoulders; only because doing so can be dangerous. And so, humans have a tendency to look directly in front of them. This fact can be used to strategically place items throughout the store: i.e., hot ticket items ought be placed at the end of aisles, because doing so will ensure the consumer can see it.


Ideasinhat is a business development analyst and longtime reader of academic literature. He writes books and essays on science and philosophy, and posts them to this website. The essays, as with the books, cover topics from psychology, philosophy, and cognitive science to economics, politics, and law.

Leave a Reply