There has to be a payoff though. BitTorrent is actually pretty hard to get working correctly, track down the torrent files... people do it because it's the only way to get some content and a way to get content you'd otherwise have to pay for. With social media, there's not much reward and most people's friends already post for free on other networks. Not saying it's not worthwhile, but it's hard to extract this lesson from BitTorrent.