Designing supermarkets.

The produce is over here, the dairy's over there. The soft drink specials are at the ends of the aisles, the candy's at the checkout. Always.

A visit to your local supermarket isn't as haphazard as it seems. It's been laid out so that you spend as much as possible on what the store wants you to buy. And that's often more than you came in for, as we learned when we spoke to supermarket industry insiders.

Here's how a typical supermarket is designed to maximize sales.

ON THE EDGE

The more time you spend shopping along the sides and back of the supermarket, the more money the store makes. About half its profits come from perimeter items like fruits and veggies, milk and cheese, and meat, poultry, and fish. That's also where you'll find the bakery, the salad bar, and the deli. If a store wants to distinguish itself from its competitors, it's got to be here.

SPACE EATERS

Some foods are so profitable that they command their own aisles. Breakfast cereals bring in more dollars per foot of shelf space than any other product in the interior of the store. So most supermarkets give cereals plenty of space.

Soft drinks aren't as profitable...at least not on paper. But beverage manufacturers sweeten the pot with so much free merchandise and cash rebates that carbonated soft drinks end up being one of the biggest money-makers in a typical store.

THE SCAN SCAM

Checkout scanning errors may be beeping shoppers out of more than $1 billion a year. Last year, researchers in Southern California found that close to one out of every ten scans was wrong. Three out of four mistakes favored (surprise) the supermarkets.

"It's a problem wherever we've looked," says Ken Butcher, coordinator of weights and measures for the National Institute of Standards and Technology.

What can you do? Watch the scanner display, for one thing. Pay particular attention to sale items. The lower price may not have been entered into the computer.

PAYING FOR SPACE

Every year, grocery chains are offered more than 15,000 new products, nearly all of which will fail. How do stores decide which ones to stock?

Moolah, in some cases. Large supermarkets often require manufacturers to pay for shelf space. "Slotting fees," as they're called, can range from $5,000 to $25,000 per supermarket chain for each new food. The small local tofu cheese plant seldom has that kind of money to throw around.

IN "PRISON"

Some supermarket insiders call the aisles of the store the "prison." Once you're in one, you're stuck until you come out the other end. The "prison" is where most of the less-profitable (for the store) national and regional name brands are, so the more time you spend there, the less time you'll spend along the perimeter...buying higher-profit items.

THE MEATING PLACE

Why are the meat, poultry, and seafood displays almost always along the back of the supermarket? So that you'll see them every time you emerge from an aisle. Not a bad place to put the most profitable sections of the store.

GOING TO THE DAIRY

Why are the dairy products usually as far away from the entrance as possible? Most everybody buys milk when they shop. To reach it, they've got to walk through a good chunk of the supermarket, often along the perimeter. That's right where the store wants shoppers.

Also, stores like to "anchor" a display by putting popular items at each end. That's why milk, for example, is often at one end of the dairy case and margarine and butter at the other. You've got to run the gauntlet of cheeses, yogurts, dips, etc. to get what you came for.

PRODUCTIVE PRODUCE

Think it's a coincidence that you almost always have to walk through the produce department when you enter a supermarket? The look of those shiny, neatly stacked fruits and vegetables is the most important influence on where people decide to shop.

It also doesn't hurt that produce is the second most profitable section (meat is first). While it occupies a little over ten percent of the typical supermarket, it brings in close to 20 percent of the store's profits.