This puts me in class #4, which Chad claims is common for spammers.
I don't necessarily disagree that a lot of spammers are in that class, but might need more nuance.
I've long thought about the follower/following ratio, though. In a second when a higher "class" twitterer follows you, there's something about their follower/following ratio that indicates the "value" of that follow.
For example, if someone with 20,000 followers and 20,000 following starts following you, it just doesn't seem as "special" as someone with 20,000 followers and 200 following starting to follow you.
Chad has tweaked his gist to point out that the "suspicious" ones (which he now calls "gamers") in class #4 are the ones with almost 1:1 follower/following ratios
I have seen people in the 10,000-99,999 follower class following > 999. @Scobleizer is a good example.
Actually, I misread. Scoble has > 200,000 followers so is in class 7.
The high follower/low following user giving you a follow or RT feels special because it means a popular/prominent person with limited attention values is spending some attention on you.
More generally, I've always wondered with orders-of-magnitude: isn't it misleading to think of, say 2,000 and 9,000 in the same order-of-magnitude?
Shouldn't the test be whether log_10 of the ratio is < 0.5 ? (i.e. ratio is less than √10 ?)
In other words 9,000 and 2,000 are not in the same order of magnitude because their ratio is 4.5.