Why We Buy: The Science of Shopping

In Why We Buy: The Science of Shopping, author Paco Underhill argues that people make purchases not so much because they are useful and sensible but because they are part of a pleasing shopping experience. First published in 2000 and revised for the Internet Age in 2009, Why We Buy became an international bestseller and has been translated into 27 languages. The 2009 Kindle edition (ASIN: B001QA4SY2) is the basis for this guide.

Underhill, an environmental psychologist, is founder and CEO of market research company Envirosell, Inc. His teams of researchers observe buyer behaviors in stores, making detailed notes and recording videos to learn precisely how patrons respond to displays, signage, store layouts, and myriad other details of the shopping experience. Envirosell’s clients include Microsoft, McDonald’s, Starbucks, Estée Lauder, Hewlett-Packard, Verizon, Sam's Club, Pepsi-Co, Adidas, and Unilever.

Why We Buy is divided into five parts, each focusing on a different aspect of buyer behavior. Part 1 explains how every attribute of a retail establishment, from the parking lot to the size of the store aisles, can affect what, and how much, shoppers will buy. A small change in the positioning of a display or the arrangement of shelving can boost sales; the wrong wording on a sign can cause merchandise to go unsold. Many retail executives are largely unaware of these details, and their businesses suffer as a result.

Part 2 points out that human physiology limits the way people shop. They tend to enter stores in a certain way, a tendency that affects which displays they’ll look at and which they’ll ignore. People have only two hands, and accounting for this can have a serious effect on how much they’ll buy. Customers wander through large stores in a certain pattern, and if the floor plan doesn’t account for this, entire departments will go unvisited. Patrons study some signs and ignore others. They also improvise, selecting merchandise in surprising ways or sitting in the wrong places, to the consternation of sellers.

In Part 3, Underhill provides a detailed description of the differences in shopping styles of men and women. A feminist revolution in retailing has greatly reduced these contrasts, but many still remain—women’s attention to detail and men’s impulsive hurry, for example—and store owners must take them into account if they’re to stay afloat in a rapidly changing retail environment. Part 3 also touches on the different buying styles and needs of the elderly, as well as the power of children to influence their parents’ purchases.

Details of store sales get a close look in Part 4. Shoppers need to touch and heft merchandise; they become impatient if made to wait, especially at checkout; and they respond positively to products that capture their attention. Also discussed are the Big Three elements of marketing: store design, merchandise selection, and staff behavior.

Part 5 ventures overseas to explore international sales and the shopping habits of different countries. Envirosell branched out to Europe, South America, India, Mexico, and Japan, in the process learning the subtleties of various cultures and their preferences. The company also learned that most shopping behavior is similar the world over. Part 5 also looks at the threat e-commerce poses to brick-and-mortar stores.

Throughout the book, Underhill explains the mistakes retailers make and how to fix them while illuminating a great deal about readers’ own tendencies when visiting stores, potentially making us more astute at recognizing places that offer the shopping experience we prefer.