Poor AOL CEO Randy Falco. He believes that acquiring the social network Bebo for $850 million put AOL in a "leading position" in social networking. Everyone else thinks the buy was a joke — including Bebo cofounder Michael Birch. Asked at an event yesterday about the purchase price, Birch said, "850 million is an interesting number. It's a lot bigger than some numbers and a lot smaller than some numbers. It's not a prime number." Asked how AOL bid itself up to $850 million, Birch said $800 million of it was due Bebo's popularity in Fiji. "Fiji is an up-and-coming market," the Birch told the crowd. Don't wonder why he's so giddy. Birch and his cofounder, his wife Xochi, earned $595 million on the deal.