There is at least one study that suggests that Facebook advertising may have helped influence an election. Journalist Simon Owens pointed to a 2011 Facebook post that outlined an evaluation of ads in a Florida ballot measure in 2010. The group Vote NO on 8 bought Facebook ads in Dade and Broward Counties to argue against the proposition, which then failed. Not only was there a big difference in the vote in the two counties where ads ran (19 percent more opposition), but people who were exposed to more online advertising voted 17 points against the proposition than those who saw fewer spots. Owens notes the results from a poll taken after the fact: “heavy web users who were on Facebook were 10 points more likely to vote no on 8 than Democrats (who may or may not have seen the ads) were.”
We already knew that Facebook could drive people to the polls. In 2010, its experiment with an “I Voted!” button increased turnout by 340,000 during that year’s midterms. In 2012, a different experiment ensured a select group of users saw more hard news as Election Day approached. The group that saw more hard news apparently turned out 3 percentage points more heavily.