Surprise Me

If one store promises 30 percent off sweaters while another offers a discount of either 20 or 30 percent, common sense suggests choosing the first shop every time. But the uncertainty of the second scheme may actually attract more customers than the sure thing, according to new findings in the Journal of Consumer Research.

In one experiment, subjects who were promised either three or five "points" for each lap they ran completed nearly twice as many as those who always got five. In another, participants received coupons for every Band-Aid they purchased. Some always received 10-cent coupons, some randomly got either 5- or 10-cent ones, and some saw the coupon's lower or higher value in advance. Those whose rewards were a surprise bought significantly more Band-Aids.

"Satisfying our curiosity is so rewarding that it reinforces our behavior," says lead author Luxi Shen, an assistant professor of marketing at the Chinese University of Hong Kong. Some products, like Kinder Eggs or scratch-off coupons, already rely on the element of surprise to boost sales. Other companies and even policymakers could benefit from uncertain rewards, Shen says: If machines that pay users for collected recyclables offered surprise bonuses, for instance, recycling might be even more appealing.