Half their customers won’t use it again. On June 11 I suggested here that Groupon’s founder was a fool to turn down someone’s (Google’s?) huge buy-out offer. I’d tried using it and found it pretty worthless and that was a consumer, not a small business owner who has to pay to participate. I didn’t buy Dunkin Donuts at $47 today and I’m sure not buying Groupon’s pending ipo. I wonder if anyone will?