Just read this article:
http://www.msnbc.msn.com/id/45398235/ns/world_news-europe/t/cupcakes-sma...

Apparently, the business owner got on groupon... was a massive hit and now, beacause of the amazing deal, is now faced with almost 20K in profit losses.
Maybe the owners could put a cap? Say this deal for a maximum of 100 people... not thousands!