>Is Groupon's revenue sustainable? I thought companies were complaining that they lost money by participating, which would indicate to me that it's not sustainable business.
Someone wrote a bad article with worse graphs showing that 40% of people did not make more money while the promotion was going on. It had horrible methodology, and didn't even point out the food service business loses money on MOST things it does, and this is actually a very small rate of loss for "things you can do to boost sales".
[Not associated with nor have I ever used groupon]