“Unable to understand how or why the person we see behaves as he does, we attribute his behavior to a person we cannot see, whose behavior we cannot explain either but about whom we are not inclined to ask questions.” – B.F. Skinner (Beyond Freedom and Dignity)

According to a recent article in Forbes Small Business, Paco Underhill has spent the past 20 years trying to figure out why consumers buy some things but not others. What he’s learned has made his consulting business (Envirosell, NYC) one of the most successful and popular in the megabillion-dollar retail market.

Underhill teaches retail stores to be careful about the “transition zone” — the space just inside the door where shoppers slow down to browsing speed and adjust their eyes to indoor lighting. “Don’t try to sell them anything of value in that area,” Underhill advises.

Underhill can also tell you that the vast majority of U.S. shoppers turn to the right after they enter a store. He can’t tell you why that is, but he’s absolutely sure it’s true.

He knows it’s true, because he doesn’t rely on conventional market research. He doesn’t conduct customer surveys. He doesn’t consult with academic experts. He doesn’t theorize. What he does do is go into shops and malls around the country and videotape customer behavior.

Using hidden cameras and human “trackers” who follow customers and document their every move, Underhill reviews the buying habits of thousands of American shoppers. An analysis of those findings is contained in his book, “Why We Buy: The Science of Shopping.”

It’s because Underhill pays attention to customer habits — and ignores customer comments — that he has been able to come up with advice that puts extra dollars on his clients’ bottom lines.

Underhill knows, for example, that sales suffer drastically when displays are so close together that shoppers bump into one another. He is also certain that most stores would enjoy a dramatic increase in sales by installing more comfortable chairs in and around display items. Although chairs take up space that could be devoted to products, they allow tired shoppers to sit down and relax. The longer you can keep a shopper in your store, Underhill knows, the more he will buy.

Underhill is good — and his clients are grateful — because his business is based on a very important realization: What people tell you they do and want to do is very often completely at odds with their actual behavior.

How does this apply to your business?

Think about how much you know about your customers’ behavior. Forget for a moment the “truths” that have been handed to you — by your mentors or consultants or the pundits whose advice you read — and ask yourself, “What do I really know for sure?”

What specific shopping/buying behaviors have you actually observed?

How do you know your advertising really works? (As compared with whatever else you could have done.)

What concrete evidence is there to support your marketing, product design, packaging, and pricing?

It is sometimes said that direct marketing is a “what” — not a “why” — business. I’m not entirely comfortable with that maxim, because I do believe in thinking about “whys.” But I am completely sure that paying attention to the “what” of what they do, and not the “why” of what they say they do, is the way to find the answers you need.