FWIW, Cory Doctorow already dealt with this issue in "Down and Out in the Magic Kingdom". In it, the measure of social capital is called Whuffie, and there were multiple scores based on it. Mentioned in the book were:
- absolute Whuffie (Which, contrary to the article's title, is meaningful. An absolute measure of clout is what's being implied by the observation that everyone knows who Barack Obama is, and the number of people who know much about me can be measured in the dozens.)
- 'right-handed' Whuffie, which is a measure of a person's reputation among people you regard highly. Think "personalized Google results."
- 'left-handed' Whuffie, which measures a person's reputation among people you regard poorly.
I did write an influence algorithm for a previous startup in which that same friend was getting a great score. So it's possible to get it right. Klout doesn't.
What Klout gets right is self-promotion: twitter addicts will tweet and retweet their influence, thus promoting Klout. Smart play by Klout.
One number won't tell you the information you need to answer these questions.
While knowing the horsepower, dimensions, top speed, and durability of a car would certainly be better for some people than a simple "car score", that "car score" might in fact be useful to a large number of people.
This is something I've given a lot of thought to and I'm working on implementing such a system.
Here's hoping that theory keeps holding up to reality.