I see nothing special about groupon. I signed up and for two weeks got nothing but crappy offers. I live in san francisco and most of the deals were for businesses far away. Sfgate,(the local newspaper), offers great daily deals. So does travelzoo and goldstar. Chevy's is always offering two for one dinners. Safeway, along with every other grocery store has buy one, get one free. There's coupons.com, ebay, amazon, etc. Groupon is just a digital coupon site, which probably won't even exist in a few years. It has nothing proprietary. I have no position in this stock- just watching it for entertainment.
a part of marketing-concepts, but daily deals are not a "The-Winner-Takes-It-All-Business", because the net-workings-effects are limited and lot of compeitors were exist and were winning market-shares.