I’m going to bet that the Portable Social Graph is going to be the next big thing in social marketing.

The idea of the plain old social graph has been around for several years. Basically, this term refers to the representation of our relationships on the web. The graph has long been recognized as valuable information, both for the owner (you and me) and for social networks.

The problem has always been that you have to replicate it on many different sites. Two years ago an influential article by Brad Fitzgerald, a programmer, proposed that you should be able to move your graph around the web with you.

Now the idea of the Portable Social Graph has really taken off. In May, web guru Jeffrey Rayport, writing in Business Week said that:

“…new tools will allow members to take their social-media identities with them when they go to other Web sites. Once wedded to a single networking platform, a member’s “social graph” password, profile, list of friends is becoming portable. In other words, as they surf the Web, users increasingly will be able to define themselves by their social network of origin.

That’s big. It signals that Web companies are no longer in a race to build “destination sites” that attract vast numbers of users. Instead, social networking players are racing to extend their influence over the entire Web by exporting their social features to all sites.”

An article in this month’s Wired magazine explains how central this is to Facebooks’ plan for web dominance:

“Facebook CEO Mark Zuckerberg envisions a more personalized, humanized Web, where our network of friends, colleagues, peers, and family is our primary source of information, just as it is offline. In Zuckerberg’s vision, users will query this “social graph” to find a doctor, the best camera, or someone to hire—rather than tapping the cold mathematics of a Google search. “

Facebook has already taken two big steps towards achieving this vision. Facebook Connect, launched in December 2008, is a network of more than ten thousand independent sites that allows Facebook users to use their friend’s details. So you can go to Delicious and see what your friends bookmarked or go to CNN and see what stories they read. In April, Facebook launched Open Stream API, which allows you to see friends’ newsfeeds from any site, not just Facebook. To understand the full significance of this for marketers, you should take a look at a presentation that Shiv Singh of Razorfish made in December of last year. He speculates about what could happen when Facebook Connnect is linked to Amazon or iTunes, for example. You can now get friends’ recommendations right at the point of purchase. All of this works, of course, because friends are the most trusted and sought after sources of advice on just about everything, as countless surveys have shown us. What does this mean for us? Firstly it vindicates what Mark Earls has been saying with his “herd” theory for some time now. It means that our targeting should be aimed much more towards social groups than individuals. It also means we should turn our web analytics away from the sites and towards the individuals that use them. They are going to be keepers of their own graphs. We should make friends with them quickly! More specifically, we should target those not only with the largest social graphs, but the most active. The key is probably to find those with the greatest inner circles - friends they are close to and contact frequently. How do we measure that?