From the article: "you've checked in for the tenth time and earned a free espresso drink."

Foursquare, and the users of foursquare, would love to see this but the businesses themselves would not. I worked for a targeted coupon agency and the kind of people who routinely visit and buy your product are exactly the kind of people you DO NOT want to give coupons to. These people are already loyal customers. Coupons are more effective if they target either new users (target starbucks customers to get a free coffee to visit our cafe instead) or increased consumption (if you buy a large coffee get a discount on buying our ice cream).