I know that this election's surprise - Bernie Sanders - owes his success to a grassroots movement organized via social media. The reasons for that are many. There is widespread resentment towards the political establishment among millennials, and so they were receptive to his message.
But simply liking him is not enough. He would have needed an initial critical mass of supporters. If his supporters sensed that they are not many, they would have dispersed on their own, believing he's just another oddity, an also-ran at the election.
Wikipedia says that he announced his candidacy from the Capitol lawn. I assume it would be a YouTube video, since I doubt any mass-media would have broadcast it.
So imagine Point X, where he posts a YouTube video. This video has maybe 20-30 views. Now let's say there's Point Y, where he has a self-sustaining community of 100,000 supporters.
From Point X to Point Y, how much time passed? Did it take him 10 days, or 10 weeks, or 10 months to gain these initial 100,000 supporters? Through which communities did knowledge about him spread - did it start from an initial post on Reddit that hit frontpage, or was he already popular on Twitter and Facebook and spread from there to Reddit?
I am asking because I suspect that Reddit.com gave the initial impetus to his movement. If the site and its community can create movements that can potentially influence American elections, then that can be a very interesting development in politics.