To help visualize that activity, Facebook's set up a real-time map showing exactly when someone clicks the "I voted" button. It counts the density of clicks for a given area, and individual clicks show up as blips on the map. From the data Facebook has gathered so far, it seems nearly 40 percent of "I voted" clicks came from women aged 25 to 44. Men are sharing at far lower rates across the board, though.
Facebook's "I voted" button isn't just a fun way to tell friends that you've done your civic duty; it's actually part of a much larger experiment to determine what Facebook's effects are on voter turnout. As Facebook has claimed previously, the social network drove 340,000 extra people to the polls in 2010.
Here's what this year's "I voted" heat map looks like, as a GIF. Click here for a larger version.