The ultimate in peer influence

There has got to be a better argument out there for social networking than "everybody's doing it." I mean, really? I understand the underlying message... that whether you are out there or not, others are, and you can't change that. But it seems to me there should be some more concrete evidence to make the argument. Although, if you think about it, the peer pressure angle might make the most sense. I mean, we are talking about peer influence, and what illustrates the point better then peer pressure itself?