In other words: Facebook isn't worth $10B.

Be careful with that logic. It applied to Microsoft in 1990, when their stock was less than $1/share (split-adjusted).

Yes, it did. Google too I imagine.

There are way more overvalued Geocities' out there than undervalued Microsoft's though.

Facebook is not Microsoft.

One year ago, FB was "worth" $2B, now it's "worth" $10B and this time next year it will be worth nothing.

We're in another bubble and it's about to burst as recession hits in and ad spending dries up.

What recession? I think the current Federal Reserve would lower interest rates into the negative to keep Wall Street booming.

Not a meaningful statistic. A site can increase in users and still drop in the rankings. Wikipedia's rise does not equal some other site's fall.