Users 18 and over will be greeted by a “Register Now” button in their News Feed starting Friday, as Facebook launches its first nationwide voter registration campaign for the next four days, the social media giant said.

Facebook (FB) has experimented with influencing users to vote in the past. A single Election Day reminder from Facebook in 2010 may have influenced some 340,000 people to go to the polls, according to 2012 study published in the journal Nature.

How many Facebook users will see this year’s message is unclear, but the 2012 study found that the incentive is in seeing friends who share that they voted.

The company wants to engage users first by getting them to register, and then by reminding them to vote and presenting the final results. Facebook sees itself as uniquely positioned to do this because of its large user base.

“We thought we had a unique ability and responsibility to show people this reminder that they should be checking their registration so they can participate in the election,” Katie Harbath, Facebook’s director of government outreach, told USA Today.

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Instagram will also get involved by making a similar push next week, according to Facebook.

This story was originally published on Time.com.