I haven't felt this strongly about shorting a stock long-term in a long time. But I don't know how long the short-term irrational exuberance is going to last - will it wipe out my investment before the stock crashes down? I haven't seen one pro-Groupon (or general daily deals) analyses that says anything different than "it gets people in the door and generates buzz" which I think is nothing more than fuzzy PR talk si…
I'd be more worried about the borrowing costs killing you.
Small float, check Hedgies got their pop and exit, check Lots of short interest, check
it's going to cost you dearly to short.