A new study from researchers at Georgia Tech (PDF) that we found via Poynter shows what really matters in getting your Twitter followers to grow.

The No. 1 factor is network overlap—when you see that your friends follow an account, you’re far more likely to follow it, too. Other measures of popularity, like the frequency with which your tweets are retweeted, matter too. Providing actual information is positively correlated with growth. Frequent tweeting actually helps.

Expressing negative sentiments or treating your account like a broadcast mechanism—i.e., not really addressing your audience—slows follower growth down. Don’t be a blowhard or a downer!

One key learning for Twitter insiders: Using hashtags, those keywords that start with a hash or pound mark (“#”), is popular with longtime Twitter users and technology insiders. But it’s a turnoff for most people.