How Twitter's Trending Algorithm Picks Its Topics
The list of "trending topics" on the right side of Twitter's home page is a coveted spot because millions of people see it. It often reflects what's hot in the news, from the death of Steve Jobs to Kim Kardashian's latest exploits.
Sometimes a topic that seems hot, like Occupy Wall Street, doesn't trend, leading some activists to charge Twitter with censorship. But the complex algorithms that determine trending topics are intended to find what's trending in the moment, and not what's been around for a long time.
Getting a spot on the trending list has become so important that television programs hire consultants to help them get there.
Jason Pollock, a social media consultant, says the singing competition The Voice set the tone for Twitter interaction. On the show, teams of young singers get coached by stars like Christina Aguilera. The Voice became one of the most popular singing competitions on TV this year with the help of Twitter.
Pollock says that as competitors are training for the competition, they tweet with some help from paid staff. They put pound signs in front of catchy phrases to create hashtags, like #TeamNakia. "They had them really operating fast. ... They had hashtags going and they were asking questions and doing polls and really engaging stuff," Pollock says.
When those hashtags hit the trending topics list on Twitter, more people started to watch The Voice on TV.
"If you start trending on Twitter, people on Twitter will turn that show on," Pollock explains. "Everyone is obsessed about the ratings — well, here's a new tool to up your ratings."
Hashtags Over Time
Social media company SocialFlow looked at the entire Twitter output over the course of a few weeks to see when different hashtags became popular. The #ThankYouSteve spike occurred in response to Steve Jobs' death; other hashtags responded to TV specials or memes that became popular. The #OccupyWallStreet hashtag, in red, has a more enduring popularity over time than the spikes.