How has an understanding of consumer behaviour helped Groupon grow from 400 subscribers in Chicago in 2008 to 60 million subscribers in 40 countries today? What is the Groupon Promise? How does the Groupon Promise affect a consumer's perceived risk and cognitive dissonance? Describe the five-stage purchase decision process for a typical Groupon user. What are possible psychological and sociological influences on the Groupon consumer purchase decision process? What challenges does Groupon face in the future? What actions would you recommend related to each challenge?