While some may pronounce that Facebook is all the social we’d ever need, users clearly haven’t gotten the memo. Instead, users are rapidly adopting new interest-based social networks such as Pinterest, Instagram, Thumb, and even the very new Fitocracy. (Disclosure:BlueRun Ventures is an investor in Thumb and Foodspotting.)

The numbers tell the tale around users’ appetites for these new interest-based social networks. Pinterest, the increasingly popular virtual pinboard, crossed 10M monthly unique users in the US in January 2012, achieving 8 digits worth of monthly uniques faster than any site ever, comScore says. According to Silicon Valley uber-investor Ron Conway, Pinterest is growing like Facebook 5 years ago.

Interest-based social networks have a markedly different focus and approach than Facebook. The Pinterest, Thumb and Foodspottings of the world enable users to focus and organize around their interests first, whereas Facebook focuses on a user’s personal relationships. Facebook offers us a social utility to deepen social connectivity with our existing social graphs, while these new interest-based social networks enable users to express their interests in new, engaging ways and offer authentic, high value connectivity with new people we don’t already know. The different approaches of these interest-based services are distinct from Facebook, and they are powering the massive growth and engagement we are seeing in these new services.

On Pinterest, I can curate and express my interests in Crossfit, cars and architecture, giving me the ability to create a strongly personal identity that draws me into new social relationships with people on the basis of my interests. Similarly on Foodspotting, I can easily express my love for ramen, which in turn connects me with other ramen fans who aren’t in my current social graph.

(Source: cafecreate.com, via unexpectedtech-deactivated20130)