Google Labs – the Social Graph
Google is noting our connections and friendships online, not just our content. I am no developer (not even close) but I like the principle here which is that our online connections count.
Build critical mass on your website
With so many websites to join, users must decide where to invest significant time in adding their same connections over and over. For developers, this means it is difficult to build successful web applications that hinge upon a critical mass of users for content and interaction. With the Social Graph API, developers can now utilize public connections their users have already created in other web services. It makes information about public connections between people easily available and useful.
Only public data
The API returns web addresses of public pages and publicly declared connections between them. The API cannot access non-public information, such as private profile pages or websites accessible to a limited group of friends.
Note: what this means is that public friendships or connections are found by search engines, for example, the Utopian College of Emergency for Medicine (UCEM) has a public facebook page which can be found by anyone as Google searches it, whereas my private Facebook cannot be easily found, unless you know me, as it will not be listed by Google.
If you want to be found online, make sure your sites are public
Finally, Google engineer Brad Fitzpatrick comments:
“By supporting open Web standards for describing connections between people, web sites can add to the social infrastructure of the web.”