I think many analysts who raised an eyebrow when Google bought YouTube are eating their hat many times over.
YouTube - the wisest buy of the century, and if you don't see it, good for you. The only thing that would have topped that would have been if Google managed to buy Facebook.
I'm one of those old-school types, who thinks that a company has value only when it has a clear way of making money.
YouTube was bought for $1.65bn in 2006. It still does not charge for content which is insanely expensive for Google to stream out to all of it's customers, and in 2008 (the only year I could find figures for it independent of Google's other figures) it lost $470m in-year despite having a revenue of nearly $1bn.
Facebook also floated on the stock exchange for $104bn. In third quarter 2012 it made a loss of $57m, and the previous year 2011 it made only $227m - i.e. less than 0.3% of it's valuation in profit (and since most of that was raised by selling shares, it's a pretty spurious profit too).
Let's put that in perspective. Microsoft made as profit in the three months to September 2012 a stonking $4.5bn. And their shares dropped because it was 22% lower than the same period the previous year.
In 2011, Apple took home $8.2bn to the bank in profit. That's not revenue. That's profit.
So no, as a cold-blooded capitalist, I don't really see Google and Facebook as good examples of companies that Microsoft should be worried about. When they start making real money, rather than just being able to raise money on the stock market, then, and only then should Microsoft be worried that the market is shifting.
If I were boss of Microsoft, I'd be looking at Google and Facebook as wannabes. It's companies like Amazon and Apple that I'd be worried about. For one, they know how to make money.