Slashdot points to a new patent by Google on “network node targeting”, namely:

A computer-implemented method for displaying advertisements to members of a network comprises identifying one or more communities of members, identifying one or more influencers in the one or more communities, and placing one or more advertisements at the profiles of one or more members in the identified one or more communities.

“Doing so will ‘provide advertisers with the option of targeting either all members in the community or advertising only on the profile of the influencer, thereby targeting the entire community,’ explains Google.

In other words, they’ve developed an algorithm to find the FIC when really all they had to do was ask.