A fascinating article in the latest TIME delves into the strategies supermarkets use to encourage more purchases from their shoppers.

Among the findings:

Over several months of experimenting, the team noticed that using a dollar sign in front of the price decreases shoppers’ likelihood of making the purchase. The dollar sign is a symbol of cost rather than gain. Removing the sign helps the consumer sidestep the harsh reality of outstanding bills and longer-term financial concerns. No doubt the larger cart and the floor tiles also played their part, but what was most surprising was the impulse to hoard. The dictum allowing only three cans per customer sealed the deal.

One suspects they’ve also spent time studying the “Yuck Factor” — a phenomenon Duke professor Gavan Fitzsimons discussed with the John Locke Foundation’s Shaftesbury Society in 2007.