Interesting view... but I'm not so sure the others (myspace, friendster, etc) failed because they became too big. If anything they didn't get enough of a network effect the point where they p enough people who were still not on social media to go onto the new thing cool thing (myspace to facebook). I guess friendster to an extent was "too big" but not in terms of network effect but because they grew too fast and their infrastructure didn't keep up making people spend 20 min just trying to login to their profile.