The point about authors is true, though: I’ve heard that ‘author’ carries more influential weight than “Phd” or “doctor” does at this point. This is probably due to the fact that getting published requires an authority figure (a publisher, with choices) has given you their stamp of approval. Note the difference in your own mind between two authors, one of which is self-published and the other from a top tier house. No comparison, is there?

In the Cialdini school of thought on the subject, “authority” matters more in areas of objectivity — which is factually better, between two choices? — while “consensus” matters more in subjective areas of taste — which fashions/music/food do many other similar people to me choose?

Given the rise of choices we all have in most all areas – from purchase decisions to reading choices – it’s hard to say what is purely objective at this point. Is an iPod better than a Sansa? Debatable. Will I poll my friends or tweet about my upcoming surgical procedure? Not bloody likely.

I agree that authority probably has more to do with retweets and links than just followers. As mentioned, retweets and links are examples of “people who take your word and take action”.

So, being popular doesn’t necessarily mean you have authority. However, I guess there still is some positive correlation between the two. And, the narrower the topic you write about, more followers probably also means more authority. I assume the correlation is stronger for narrower topics.

Maybe that is implicit though, in the fact that a narrow topic by definition hardly can be very popular! =)