Because I want my twitter stream to consist largely of people at my own level, and I have a twitter ratio of ~= 1. People with higher ratios (I follow a few, bu

Because I want my twitter stream to consist largely of people at my own level, and I have a twitter ratio of ~= 1. People with higher ratios (I follow a few, but not many) are usually so busy or important that I've no reason to follow their tweets, just as they've no reason to follow mine.