Check out Groupon’s S-1 when you get a chance. In less than 3 years, the company has accumulated losses of over $500 million.

I don’t doubt that there’s a sustainable business model buried beneath all the mirthful irreverence, but there are troubling signs that Groupon’s performance is deteriorating in mature markets– and it’s never a good sign when early investors have already jumped ship with nearly $1 billion.

Related:
The Wall Street Journal asks, “Will Investors Take Groupon’s Andrew Mason Seriously?”

UPDATE: Brett Arends at MarketWatch writes,

During the dot-com bubble, I once heard a story from a venture capitalist about a start-up that wanted to be valued at a multiple of headcount. At $5 billion, Groupon would be valued at nearly 10 times accumulated losses. Who’s to say that’s too much?