The latest rumour bouncing around Silicon Valley is that Facebook may be looking to raise another round of venture capital.

It’s an interesting idea, not least because any new funding round would force Facebook’s investors to put a valuation on the company. Peter Thiel, the site’s second-biggest investor, told us last month that Facebook and its founders think the site is worth $8bn to $10bn. It is unlikely that  VCs would be tempted by such a high valuation - far more likely that Mr Thiel was throwing the number out as a signal to potential acquirers. Still, even at a much lower valuation, the buzz around Facebook is such that it could probably raise a hundred million dollars or more for a relatively small dilution in ownership.

Peter Thiel, Jim Breyer, and a handful of other high-profile Valley luminaries have pumped more than $40m into the social networking site over the past two years, but with Mark Zuckerberg appearing increasingly intent on taking his company all the way to an IPO, a new venture round could make sense.

We sat down with Mr Zuckerberg at Facebook’s offices in downtown Palo Alto last week (article, transcript). While the subject of a new venture round didn’t come up, the Facebook founder did tell us that the company plans to expand its headcount from 300 to more than 500 this year. It is also hard at work on a new advertising system designed to take better advantage of the connections between the site’s users. Monetisation of the site has lagged behind audience growth. Making the investments necessary to turn that around is a top priority.

As a keen student of recent internet history, Mr Zuckerberg seems intent on nailing down Facebook’s revenue model ahead of any potential IPO - much like Google did before it announced plans to go public four years ago. Given what he and his team have accomplished so far, it’s not surprising that Mr Zuckerberg’s investors seem willing to give him more time to get it right.