That's true, but leverage works both ways: if the IPO flops, it's a huge hole in their portfolios.
It'll be interesting to see what effect all this public criticism of the S1 filing does to the opening day price.
I'm guessing this public criticism is pretty much limited to tech savvy audiences so far. I haven't seen Groupon get this criticized on cnn, money.com or ft yet, so the wider public is probably still thinking this is a great deal.