It scares me how little some Web 2.0 CEO's, pundits and evangelists actually seem to "know" about the value and application of social networks. One recently claimed the quality of a facebook network was proportional to the number of close friends who share many friends in common (with you). At best, this is an oversimplification. At worst, it is a characterization of social networks which begs the proverbial venture capital question --- so what is it good for, another rolodex?
Maybe with an abundance of networks to uncover, discover and build upon, our resulting enthusiasm has led us to ignore the next step. I think Facebook understands this at least, as they have turned their growth momentum over to their users via apps.
"Now that you've built up your social network, we'll let you purpose it as you please."