Because Zuckerberg doesn't have to. Microsoft owns 1.6 percent of Facebook; Li, even after doubling his take, only 0.8 percent. Neither stake is large enough to merit a board seat. Andreessen is, like Thiel, the former CEO of PayPal, an entrepreneur-friendly choice; he bypassed Sand Hill Road altogether to raise Ning's $100-million-plus in funding.
Just yesterday, we'd heard that Zuckerberg, who owns 27 percent of Facebook, had the right to appoint two board members. That leaves him one more seat at the table to fill. Anyone want to take odds on the moneymen getting left out once again?