handwaving and hyberbole? Google has a ton of real life assets. Google Voice is a game changer, as is Android. I don't see how suddenly, based on an inflated valuation, Groupon is suddenly bigger than Google. The proof is in the pudding...time will tell.
There's someone making money off of Android, but it's hardware makers and the cell networks, not Google. What's Android's strategic relevance? More web advertising. Google Voice? Value-add for Android, maybe, but how does it add to their revenue?
I don't think Groupon will necessarily end up bigger than Google, but they may end up fairly comparable. The point is, Groupon is a fairly young startup with some growth left in it and Google is a mature, publicly-traded company. As a business (rather than as a social force or a technical harbinger), Google rounds down to web advertising. To beat Google as a business, you have to beat Google's web advertising. Groupon can do that.
To beat anybody you need to became more valuable in the everyday activities. Care to explain how Groupon can matter in the online or offline life for an average person?
By actual revenue? Google is AdWords.