Google, king of all search engines, may finally make all the existential meta data you’ve been so careful to document useful in examining the relationship between web sites.
Exactly what relationships will this API actually be able to graph? According to Google the Social graph API makes use of (XHTML Friends Network) and FOAF (Friend Of A Friend) to map social connections between various web sites.
The WordPress Blogroll uses XFN in REL tags to define relationships. TypePad Publishes FOAF data so weblogs will probably be a large part of the data that Google is able to graph.
With so many web sites 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.