Mobile Messaging and Social Media 2015 | Pew Research Center

Check the full summary for more U.S. social media and mobile messaging trends

"Facebook remains the most popular social media site – 72% of online adults are Facebook users, amounting to 62% of all American adults. Growth on the site has largely plateaued. There has not been a significant change in the overall share of users since 2012. Those on Facebook remain highly engaged with 70% saying they log on daily, including 43% who do so several times a day.
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Fully 72% of online American adults use Facebook, a proportion unchanged from September 2014. Usage continues to be especially popular among online women, 77% of whom are users. In addition, 82% of online adults ages 18 to 29 use Facebook, along with 79% of those ages 30 to 49, 64% of those ages 50 to 64 and 48% of those 65 and older."

Mobile Messaging and Social Media 2015 | Pew Research Center