There was an article about a bakery being overwhelmed by Groupon customers posted here a couple of months ago that you might find interesting: http://news.ycombinator.com/item?id=1338553
People in the HN thread I linked have other interesting things to say, too. From what I can tell, it looks like there's a ton of potential to get your name out there, but you will almost certainly have to be able to accept an initial loss to do so. I don't have any experience with it personally, though.
There was another article linked in that thread about a helicopter training school having a similar experience: http://blogs.law.harvard.edu/philg/2010/03/19/groupon-market...
People in the HN thread I linked have other interesting things to say, too. From what I can tell, it looks like there's a ton of potential to get your name out there, but you will almost certainly have to be able to accept an initial loss to do so. I don't have any experience with it personally, though.