For everyone like me who didn't understand the difference between an individual in a high k-shell and a hub: <a href="http://en.wikipedia.org/wiki/K-core" rel="nofollow">http://en.wikipedia.org/wiki/K-core</a> clarifies it nicely. (it didn't help for searching that core and shell got interchanged :))<p>That is, you can be a hub in a low k-shell, if say, you live in a town where everyone knows everyone but only the mailman ever leaves town.<p>Edit: in other words, this says that it's not about how many people you know, but how many highly-connected people you know. That's exactly what is usually informally meant by "well-connected".