Twitter works. Pay close attention to what makes Twitter work.
Create. Inform. Engage. | Journalism training, media news & how to’s
Some of these findings here are in the "Well, duh!" category – negative tweets don’t increase followers, nobody cares what you had for lunch, informational tweets perform better.
Others are quite interesting. For example "network overlap" has the highest positive effect on number of followers, follwoed by the tweet to retweet ration. Network overlap is defined as "Number of connections in-common with potential new followers."
See on www.poynter.org