A company is only worth what somebody is willing to pay for it. So after Microsoft paid $240 million for 1.6 percent of Facebook, the company's value on paper became $15 billion. Funny thing is, Facebook hasn't yet found another investor to agree to that number. The night Facebook signed its Microsoft deal, we reported a rumor that CFO Gideon Yu was close to bringing in another $500 million from private equity or hedge funds. Not true: the board had only authorized raising another $260 million. But even that hasn't come through yet.

What could be slowing investors down? Perhaps its Google's counterstrike initiative, OpenSocial. Or word of bad behavior at Facebook headquarters. Or maybe even the trouble privacy advocates are brewing in DC in an effort to limit the behavioral targeting techniques critical to Facebook's soon-to-be-launched ad network, SocialAds.

But more likely is that Facebook's funding round won't remain open for very much longer and the slow news on progress is due to Mark Zuckerberg's war on leaks inside the company. Then, too, hedge fund managers are much less chatty than venture capitalists — and word is that Facebook's valuation has priced the Valley's VCs out of this round.