How Much Are Facebook, Twitter & ...

For the moment, the valuations we have for private companies like Facebook, Twitter, and LinkedIn are based mostly on what we know from venture capital investments.

SharesPost, however, is a company that lets owners of shares in private companies sell them to prospective buyers, and they’ve just released an index detailing valuations of some of the most prominent companies in the social media space.

Here’s what they report:

Facebook: $11.5 billion

Zynga: $2.6 billion

Twitter: $1.4 billion

LinkedIn: $1.3 billion

Linden Labs (Second Life): $383 million

How close are these valuations to reality? Facebook’s most recent investment from DST valued the company at north of $10 billion, while Twitter was valued at roughly $1 billion when it took $100 million in funding back in September. In other words — likely not too far off.

SharePost also says that they’ve been involved “in the negotiations of more than $229MM worth of transactions,” so there is enough activity in their marketplace for them to make rough estimates of valuation. Their estimates also take into account venture capital investments and research reports from equity analysts.