I like this TechCrunch post by Naval Ravikant and Adam Rifkin, because it makes it clear that there is not one “social graph” that any one player can “capture”. Instead, there are many perspectives on social ties, and each application (facebook, twitter, email, linkedin, flickr, etc.) reflects different perspectives on those graphs. I suspect the successful social apps are those who have defined perspectives that map well to implicit human relationship types, and then figured out monetization models that don’t get too much in the way. The evidence suggests that the social perspectives offered by Facebook, Twitter and Linkedin to name a few all provide a good combination of user and investor value.

As Ravikant and Rifkin argue, some perspectives have a lot of commercial value, and others much less, either because they’re not interesting to people (most brand-based social networks I hope will fall in this category), or because they represent relationships which aren’t easily monetizable.

Human relationships are much richer and more colorful than (‘friends’, ‘interests’ and ‘colleagues’), however. And some of the social ties that aren’t valuable to investors are however very important to people. Figuring out how the web can support these other perspectives is, I suspect one of the big challenges of the next few years, and I expect the answer will come from sociologists, psychologists and designers working in concert with technologists.

What other perspectives on the social graph should there be on the net, and how can we make it possible for the web to reflect the breadth and variety of human relationships that truly exist?