So what is Groupon really? It's a place for bad small businesses to offer 50% off discounts.
How does Google take advantage? By undercutting Grpn's prices: Goog has 2 revenue streams!
Eventually, it will buy Grpn.
Now, take Fb: soon it will run out of the 16 billion investment and Google will buy them up just like they will Grpn.