So much for the sanctity of the ballot box: More than 1 in 5 registered voters let other people know how they voted on a social media site such as Facebook and Twitter, according to a new study from Pew Internet & American Life Project.
Some 25% of President Obama supporters posted their presidential preference, compared with 20% of those who back his Republican challenger, Mitt Romney.
Social media has emerged as a notable platform for political persuasion: 30% of registered voters have been encouraged, by family or friends, to vote for one of the candidates via a social network, the Pew study found.
Female voters were more likely to get a social media prod to support either Obama or Romney.
In the close presidential contest, face-to-face conversations remain the primary way friends or family seek to persuade others to support their candidate. Some 48% of those surveyed said they had such a conversation in the last 30 days.