>Do anything to get rid of thousands of cold calling sales people.

If I remember correctly, it sees its sales force as a competitive advantage.

Thousands of employees, slim (if any) margins... sounds a bit like Kozmo.com...

$4 billion in revenue would be much more impressive if it could scale efficiently and without a $430 million loss.

So Groupon is a massive affiliate network scheme built using humans, software and hype.

The lesson for nearly everyone here on HN, is that this market is huge! I'm signing up for Groupon, Living Social, and others, and I plan to just sit back and absorb the marketplace for a couple of months and brainstorm about how to get a piece of the pie!

Agreed. The article says that Groupon has no real moat, so that means this business model is ripe for niche players (ie, be better at, say, furniture or massages than Groupon/LivingSocial)

There's nothing wrong with low margin, look at Wal-Mart. The problem is getting the customers through the door (or in this case through the website).