"It's hard to see why, though: DST got in at a $10 billion valuation in May 2009. Facebook's user base has more than doubled since then. So its valuation should

"It's hard to see why, though: DST got in at a $10 billion valuation in May 2009. Facebook's user base has more than doubled since then. So its valuation should…quintuple?" Good point, according to Metcalfe's Law [1], it should actually only have quadrupled. [1] http://en.wikipedia.org/wiki/Metcalfes_law http://en.wikipedia.org/wiki/Metcalfes_law