А вот интересный пост про Groupon

But a September 2010 study by a Rice University professor, titled How Effective Are Groupon Promotions for Businesses?, suggested that Groupon -- and the dozens of other social-discount sites like it -- could be a far better deal for consumers than for businesses. The study was done by Associate Professor of Management Utpal M. Dholakia, who surveyed 150 businesses in 19 cities that ran Groupon offers from June 2009 to August 2010. While two-thirds of the businesses in the survey turned a profit on their promotions, more than 40 percent reported that they wouldn’t do it again.