On Friday afternoon, a funny thing happened: Mitt Romney started adding followers by the thousand on Twitter. According to this chart at Buzzfeed, they added almost 98,000 followers at the peak of the swarm. Thing is, nothing about Romney's Twitter feed changed. The campaign didn't tweet anything out of the ordinary. The numbers just started, peaked, and then declined in a perfect arc centering around the 21st and 22nd.
So far as I know, this kind of thing can only happen in one of three ways: Either you can (1.) post something that becomes viral; someone else can (2.) organize a follower gold rush for you, with a series of Twitter users encouraging their followers to follow a specific account; or (3.) you can buy followers from a disreputable service. The quality of Romney's new followers appears to be low; the majority of his new followers are mostly bots who only follow a handful of other accounts and don't ever post anything themselves. (Bot-making is one of those weird internet industries, like WoW gold-farming, that has popped up in the last few years, wherein people earn fractions of pennies to create new Twitter accounts.) The low quality indicates we're dealing with option 3. (The benefit of gaining new followers—even fake followers who don't really exist—is that it increases your rankings on Twitter, which leads more, quality followers to your feed.)
Zac Moffatt, the Romney campaign's digital director, rejected accusations that the campaign was "buying" followers for Romney, who trails Barack Obama's account by more than 16 million followers. "We have reached out to Twitter to find out additional information regarding the rapid growth," he told BuzzFeed.
I think the only options are that the Romney campaign is lying and didn't realize that the jump in followers would be noticed, or that someone else did this on behalf of the Romney campaign without their knowledge. Either way, it's another sign that the Romney campaign isn't exactly ship-shape, internally.