Phase 1: Wow! These are great deals, I'll buy a bunch.
Phase 2: I use my groupon at one of the restaurants and have a deeply flawed experience -- concluding that Groupon is the new Transmedia -- a depressing step on the path of a restaurant's extinction.
Phase 3: Wow! One of my favorite restaurants is on it! I'll get several.
Phase 4: I go to my beloved restaurant, without the groupon, and see that they have lowered both the quality of ingredients and the portion sizes. I have my first bad experience at that restaurant, and am so saddened that I probably won't return: I'd rather give my groupons away than spoil whatever happy memories I have left.
Phase 5: Groupon takes a 50% commission from the restaurant? No wonder staff are so surly to grouponsters. Does that mean their break-even number is 4x? Restaurants are told that groupon will bring new customers, but -- in my case at least -- they might as well paint a plague warning on the door.