This. There is a definite finite life cycle of social sites. Would do investors well to study the rise, domination, fall, and practical disappearance of such sites. BBSs, usenet, Compuserve, AOL (freaking bought Time-Warner!), MySpace, many others - all out to take over the world at one time, all legitimately worth vast sums at their peak, all now little more than rotting corpses. Know when to invest, know when to cash out, know when to stay away.
