Let's say a small auto-detailing business in your area offers an 80 percent discount on its service. If the coupon is well received, the shop may get so much response that it can't schedule all the appointments in the necessary time frame. If that's the case, you may be out of luck – unless the vendor extends the window of opportunity. If you find a deal that's particularly attractive or popular, contact the business first for appointment options.
Al Behrman/AP/File
Chef Paul Kendall, right, demonstrates cooking techniques while Pegg, left, and Dick Bisher look on during a cooking class at a Learning Kitchen in West Chester, Ohio. The Learning Kitchen has used Groupon and Foursquare for mobile marketing.