It is uploaded to arxiv. It won't be published in a journal, since it is a trivial and non-novel result that _broadcasters_ have a larger audience than non-famous people.
As someone who has published a graph theory paper (in a journal), I doubt this is far away from being state of the art work.
A lot of people are trying to apply graph theory in wild situations where it doesn't belong, yet this basic work on social networks and social graphs hasn't been studied in an academic way.
