[derefr]

> a single "score" cannot encompass someone's influence

I would argue the opposite. There is one ultimate "score" of a person's influence: their wealth.

While not all of a person's influence is delimited in dollars at any given time, almost every kind of influence is fungible to dollars. You can, for example, "spend" social capital by burning bridges asking friends for personal monetary loans.

It's actually pretty unclear to me whether President Obama's or Justin Bieber's influence would liquidate into a greater amount of money. But it's certainly a question that has a factual answer, and it's a useful answer, unlike a Klout score.