16 May 2012

Quora question: What techniques did Facebook's "Growth team" use to get to 500 million users - http://qr.ae/RS4ql 
Summary: figuring out the friends tipping point that gets users engaged and optimising the channels for acquisition, activation, engagement. 
"Plenty of social media services allow contact importing. But how many of them were rigorous enough to enable virtually every email importing service on the planet? I only know two at this point: Facebook and LinkedIn." 

(2000 words; via)