Ah analytics, I love them. I take all numbers with a grain of salt but it is nice to see if your efforts are paying off and what things people share or inspire a click. For example, a recent popular tweet, based on number of clicks, was a tweet about Klout with 177 clicks – clearly my followers are interested in Klout.
Some tools allow you to see who has unfollowed you and who your new followers are or even help you find new people to follow. I also find it nice to know who my biggest retweeters or mentioners were for the week and acknowledge them. I am glad I picked this question, because I have some seriously smart friends answering and they had a few surprises for me....