i see risk in this stock - it takes one government to get pissed off with facebooks flagrant disregard of changing privacy goalposts for users to something other than what they signed up for - or a major law suit - for this company to come to a crashing halt. This doesn't mean the technology wont survive. Think Napster and the fall they took for the online music sharing industry.
If i could be bothered i'd be looking at its closest competitors and their intentions for floating as the benchmark has been set with a 100B market cap, which is all market share to be lost to more niche social networking sites.