The Groupon model IMHO is not sustainable unless they can generate repeat business. It's great a system for securing guaranteed customer numbers. But with such a huge discount to attract them, and with 50% of that going to Groupon coffers, I don't see the benefit to small-medium businesses. Larger businesses could write-off the deal and attempt to either increase brand awareness or upsell instore. But even then, they're risking enforcing a consumer mentality of only buying at the discounted rate.