Supermarket Science

CHEESE

Shelving cheese near wine can nudge shoppers into impulsively buying a bottle of Bordeaux. And posting an attractive salesperson with a small selection of samples--five is often more effective than 50--seems to boost buying.

SILVER POLISH

Some products have a lucrative rub-off effect. A supermarket-strategy firm found that shoppers who buy silver polish tend to spend more than $200 a trip. So even though it's a low-turnover product, shelving experts keep it around.

KETCHUP

To capitalize on customers loyal to certain brands, supermarkets make sure that popular labels, such as Heinz ketchup and Cheerios, are easy to spot and positioned near profitable store brands.

DIAPERS

They're not shelved next to condoms because diapers don't scream "sexy." But should they be positioned alongside baby food? Given that many consumers spend just seven seconds at a particular display before selecting a product, some store planners want to encourage shoppers to grab related baby products by stocking them all in the same area. Research also suggests that diapers in opaque packaging may evoke less disgust than those in a see-through bag.

KITTY LITTER

Even before the recent pet-food scare, supermarkets had to be careful about where to put kitty litter, since its use carries a definite ick factor. Attractive, bright packaging may help, but positioning in the pet section remains a challenge.