I'll give one, both as consumer, merchant and partner. I have never owned stock in the company and don't know anybody there.
As a consumer, I've discovered tons of new restaurants and services through Groupon.
As a merchant, I ran several groupons and they kicked butt. Of course you need reasonable expectations about margin and repeat customers.
As a partner, I've referred dozens of brands to Groupon Goods, who are easy to working with, pay their bills on time and pay MORE than traditional retail channels, because there zero loss/spoilage.
I can't speak to sales tactics but my experience was virtually 100% positive.
