For me to follow someone, they have to: 1. update regularly 2. have a real name (not something like success4u) 3. somewhat related to my interests For me to unfollow, it's because: 1. they don't update for days 2. they spam 3. they don't interact but just broadcast What about you?
Most people on Twitter probably go from Twit to Twit and follow the first 5-10 people on their followers or following list. Very few probably examine carefully who they should follow. It is so easy to un-follow someone if their contributions are clouding your Tweets View. If you notice that when you follow someone that you appear at the top of their followers page. After a few days or week you're much further down the page and maybe past the 5-10 top followers on that list. If you un-follow and re-follow that same person you re-appear at the top of their followers list. This gives you re-exposure when others come to that same list and follow the top 5-10 people on the list.
I would love to hear other thoughts. I just started with Twitter, and I'm trying to make sense of it all. I would love to see something that details "Twitter Etiquette".