Being popular on Twitter is similar to being popular in high school: don't talk about yourself, stick to happy topics and avoid cliques, U.S. researchers say. Eric Gilbert, assistant professor in Georgia Tech's School of Interactive Computing, and colleagues analyzed a half-million tweets over 15 months that revealed a set of reliable predictors for building a Twitter following. Gilbert said Twitter is based mainly on weak social ties, and most followers do not know each other offline. The researchers identified 2,800 terms that conveyed positive and negative emotions. The team scored each term based on a sliding scale of positivity. They were then able to determine whether Twitter users who used each term gained or lost followers. The team discovered that certain identifiable strategies in message content and interaction with other Twitter users, as well as the structure of one's Twitter network, have a predictable effect on the number of followers. For example, Twitter "informers," users who share informational content, consistently attracted more followers than "meformers," users who shared information about themselves. The researchers said Twitter users can grow their followers by such tactics as: -- Don't talk about yourself: informational content attracts followers at a rate 30 times higher than content focused on the tweeter. -- Be happy, stay away from negative posts such as death, unemployment and poor health. -- Cool it on the hashtags: the higher a Twitter users' "hashtag ratio," the less likely they were to attract new followers. The findings were presented at the ACM Special Interest Group on Computer-Human Interaction Conference on Human Factors in Computing Systems in Paris.