Maybe I was wrong about Facebook's valuation

I've posted before about Facebook and its valuation ... not always in the most optimistic light. I'm reading a post today about rumors that Bebo is being actively shopped by AOL. Now I'm doing some very very rough calculations based on some very very vague assumptions, but I think I might have undervalued Facebook.
 
My take has always been that Facebook should be valued at about 5 times revenue. I still hold to that value and have said I would revise my numbers should I get more detail into Facebook's real revenues. Well based on the TechCrunch post, Bebo is rumored to be valued at about $200 million which supposedly is two times its current annual revenues (or $100 million). I pulled some traffic numbers from QuantCast for both these guys:

Making a very simple assumption of traffic = revenue, I'll assume that Facebook has 11.47 times the revenue of Bebo or $1.147 billion. Based on that, my new valuation for them is about $5.735 billion. Still a far cry from the $15 billion valuation they raised their last round with but not too shabby. Again, this is a very rough estimate and who knows whether I'm still above or below their true revenue number. My hope is that Facebook is doing well and that they can still grow. We all know the Bay Area could use a big employer nowadays.