They want to know why you buy

When we go shopping, most of us never think about how all those clothes, toys, games, computers, and whatever else are presented to us. We think we just go into the mall, find what we're looking for, buy it, and go home. Wrong. Most of us end up with stuff we had no intention of buying when we walked into the mall.

How does this happen? No one is forcing us to buy stuff we don't want. Well, in a way they are. It's called marketing or merchandising, and it involves such things as how the aisles are laid out, lighting, where products are placed on shelves, what is displayed in the window, and how friendly and aggressive salespeople are.

A New York-based company called Envirosell has been around for 25 years. Big stores hire Envirosell to analyze why people buy what they buy. The company looks at how people interact with the layout of a store and the products for sale there. Envirosell consultants are sometimes called "retail anthropologists." Anthropologists study how people behave in different cultures. Retail anthropologists study how people behave in a store.

Teams of researchers go to stores to do "field work." They count how many people are buying what types of products. They keep track of how many people walk into a store and don't buy anything, and where people go inside the store. They even look at how parking lots are arranged.

The founder of Envirosell, Paco Underhill, has written books about why we buy what we buy. ("Why We Buy" came out in 1999; "The Call of the Mall" was published this year.) In them, Mr. Underhill talks about how his company does research. I contacted Craig Childress, director of prototype design research at Envirosell. One of Mr. Childress's jobs is to develop ways to measure why people buy what they buy.

Childress says that he often brings skateboards when he goes into a store to research it. He asks store executives to sit on the boards and go down the aisles.

"Most designers design stores at a level aimed at someone who's 5 feet 5 inches tall," he explains. The executives on the skateboards see the aisles the way kids see them. "Oh my goodness," the executives tell him. "I'm only seeing the underside of the shelves!" Bingo, Childress says. If kids see interesting things, they'll be entertained and won't bug their parents as they shop. Even better, the kids may see things they will ask their parents to buy for them. He encourages store designers to think about the "kid perspective."

To help you understand some of the techniques that merchandisers use to study shoppers, Childress and I came up with some experiments you can do with your friends at the mall. All you need is a notebook, something to write with, and a stopwatch. (A watch with a second hand will do fine.)

Then I headed to our local mall with Jack and Clara Gallagher, ages 10 and 11, to try them out. We spent an hour unraveling some mall mysteries.

Experiment No. 1: Rating window displays. Think about the way you approach a store in a mall: You walk toward it from either direction, right? Look at several window displays. Are they arranged so you can see them from both sides? Or do you have to stand right in front of the window to figure out what the store is selling?

We looked at several window displays. We found one that was terrible, one that was OK, and one that was good. The terrible window display was for a perfume store. It had little bottles of perfume sitting on some low blocks. The store sign was about seven feet off the ground. From eight feet away, all you saw were some indistinguishable bottles near the ground and the back wall of the store. Way over your head, where you didn't notice it, was the sign. Forget trying to "read" that window from either side. The OK window, a clothing store, had headless mannequins dressed in the store's clothes. Big pieces of fabric hung behind the mannequins so you weren't distracted by the rest of the store. Problem: They faced forward so it was hard to see the clothes well unless you stood right in front of the window.

The window that worked best was for a kid's store. Once again, dressed mannequins were featured. But this time they were posed like action figures. No matter which direction you approached, one of the figures faced you. Jack, Clara, and I thought the window "worked." It made us want to enter the store.

Experiment No. 2: Who's buying? For five minutes, count how many people enter a store and how many leave the store carrying a store bag (meaning they bought something). This is how researchers measure a store's "conversion ratio."

Childress says that a conversion ratio of 25 to 35 percent is good. That means between one-quarter and one-third of the people who go into a store end up buying something. We stood outside a nationally known "hip" clothing store. I staked out one entrance and Jack and Clara sat on a bench at the other. We had walkie-talkies, so I cued them when to start. Five minutes later, I told them to stop. We compiled our data: 34 people went into the store, and 10 came out with the store's shopping bags. The conversion ratio was 29 percent (10 divided by 34). Not bad.

Experiment No. 3: Where do the shoppers go? Divide a store into equal sections and assign one person to each section. Each person counts the number of people in his or her section over a five-minute period. Do this three times. This will give you three snapshots of store density (how shoppers are spread through the store).

The manager of a store well-known for its outdoor wear gave us permission to conduct our experiment. We chose this store because, while it is fairly small, different things take place in each section. The front of the store had racks of clothes to browse through. The middle section included the cashier station. The back of the store had specialty items for sale. When we looked at our store-density "snapshots," we found there were more people in the back of the store than at the front. But the middle section had the most people - probably because that's where the cash register was. People from the front and the back ended up in the middle if they wanted to buy something.

Much of what we looked at seemed like common sense, but store designers have to figure all this out when they put a store together. They think about such things as where to put shopping baskets, what kind of background music works best in a particular store, how salesclerks should dress to attract the right customers, whether to hang clothes on hangers or fold them and put them on tables.

Next time you go to the mall, check it out.

In 1954, designer Victor Gruen began work on Southdale Shopping Center (now Southdale Mall) in Edina, Minn. It cost $20 million and contained 72 stores, including two 'anchor' department stores. Amazingly, Gruen's enclosed mall design is very similar to those of most malls today.

Gruen's was the first modern shopping mall, but its roots in America go back to the early 1800s. That's when builders began to experiment with arcades that had many stores under one roof. (The concept didn't catch on back then. The Arcade in Providence, R.I., built in 1828, is the oldest one of these still open for business.)

Before Gruen's modern mall there were shopping centers and strip malls - rows of connected stores with windows and doors that faced a parking lot. Gruen took the strip mall, connected the ends, turned it inside out, enclosed the whole thing so it could be warm in the winter and cool in the summer, and placed it in the middle of a huge parking lot for 5,000 cars.

Victor Gruen's two-story design with escalators at either end has yet to be improved upon. He figured out that people would pass twice as many stores if they walked in one direction on one floor, then took the escalator and walked back on the other floor toward where they'd parked their cars.

• The most expensive items on store shelves are placed at eye level. Look above or below that shelf for bargains.

• The average consumer sizes up a store and decides whether or not to shop there just 10 seconds after walking in.

• American teens (ages 12-19) spent a whopping $175 billion in 2003. Most went for clothes (40 percent), followed by entertainment (22 percent), food (8 percent), and personal care (6 percent). On average, boys outspent girls: $71 per week versus $61.50.

• Almost all the music you hear in stores is instrumental - no words. Store owners don't want you to consciously listen to (and so be distracted by) the music. The exception: music stores.

• Paco Underhill of Envirosell tells stores to be aware of what we'll call the 'bottom brush' effect: Shoppers won't bend over to buy products on the bottom shelf unless they really want them. Customers also avoid racks set so close together that they may be jostled by fellow shoppers.

• Most people feel they spend more time in line than they really do. That's why stores put things for you to look at or read (or impulsively buy) as you stand in line. That way, you don't feel as though you've waited so long.