So now Google is jumping on the Social Operating System (SOS) bandwagon with Google Friend Connect.

One way this will work is sites like mine, for example, will be able to add a widget so that site visitors can “friend” the site itself (like a fanclub), and can also access their own social networking friends in some way (perhaps to recommend the site), without having to go back to the parent Facebook/MySpace/Orkut website. For a website like mine, this should be very useful — I’d love to know who my readers are. A 26econ Facebook group would do basically the same thing, but I doubt that many people would bother to go to Facebook and join it. A widget-based version directly on a third-party website would be much more convenient for users.

From Google’s point of view, supporting social features on third-party sites should help with targeted advertising. Currently their Adsense ads are targeted towards the site’s content. Having a network of site-specific friends would allow Google to use both site and user characteristics to target ads, which should be more effective. For Facebook and MySpace, generating revenues is more problematic, because they are geared towards selling advertising on their own sites. The most logical thing for them to do is to build their own advertising networks for third-party sites to compete with Adsense.

The other interesting thing is that this adds an additional ’side’ to social networks. The formerly two-sided platforms (users; advertisers) just became three-sided (users; websites; advertisers). Previously, the basic metric for a social network’s success was pretty much the number of users that it had. Now the number of websites counts as well. It’ll be interesting to see how the SOSs compete in these two dimensions.