You are way more optimistic than I am. Reconnecting with old acquaintances is just one (outdated, as you mention) use case of social media. They have become mu

You are way more optimistic than I am. Reconnecting with old acquaintances is just one (outdated, as you mention) use case of social media. They have become much more subversive (and profitable) as media/advertising engines. They'll survive as long as companies are willing to put money into advertising and enough people are influenced by (not even "suckered by") the ads. So basically forever.