I wrote a post a while back where I did a back of the envelope calculation of Facebook's valuation - somewhere between $1.5 to $1.75 billion. I based it on revenue numbers of about $300M to $350M (5 times revenue was my rationalization) and if Facebook revenues are higher, I'll revise that estimate up.
I was watching Tech Ticker today where Sarah Lacy was interviewing Paul Kedrosky about Facebook's outlook for 2009. The question of valuation came up and Paul stated his estimate was about $500M to $600M. Though I don't agree with that valuation, I can see how he came up with this number. The online advertising market has contracted since last year so even though Facebook may be growing in revenue, I don't see how it can grow in the most important number of revenue per user. Sarah's response showed she was well on the other side of the fence in her defense of Facebook, which I don't agree with, as well. Her argument that Facebook was still an early stage private company in product development mode and not focusing on revenue is a bit off. Facebook has been around since 2004 and has made a few attempts at monetizing its traffic with no real success. Her other assertion that Facebook was similar to Google and that eventually they'll pull it off is also a stretch. Google did not raise $516M (it raised about $25M) and in its 5th year of operation made almost $1.5B in sales and over $100M in net income. I don't know what Facebook's revenues are like but I doubt it's more than $400M-$500M and they're most certainly not profitable (break-even at best). The fallacy in comparing Facebook with Google is that it costs Google far less to support each user on its system than Facebook AND it generates far more revenue per user than Facebook does. Until Facebook can find the magic bullet, I can't justify giving it a higher valuation.