Twitter says its ads pay off for political candidates

The study by the marketing firm Compete found the average Twitter user was 68 percent more likely to visit a campaign donation page than the average Internet user.

The likelihood increases when Twitter users are exposed to political tweets either from those they follow or "promoted" or paid messages.

"Twitter users exposed to any of these kinds of political tweets are almost twice as likely (97 percent) as other Twitter users to visit an online political donation page," said Twitter's head of political ad sales, Peter Greenberger.

Greenberger said in a blog post that these Twitter users are more likely to donate and also become more engaged in a campaign.

He said the data didn't allow an analysis of individual campaigns but that increased donation rates by Twitter users were found to be very similar across all candidates and parties.

"We have always known that Twitter users are politically engaged; now we know that exposure to political tweets drives political contributions," he said.