Facebook like button years of questions from the public about whether it had an intention to incorporate a "Dislike" button, Facebook officially rolled out "Reactions" to users worldwide on February 24, 2016, letting users long-press on the like button for an option to use one of five pre-defined emotions, including "Love", "Haha", "Wow", "Sad", or "Angry". Reactions were also extended to comments in May 2017. The like button is one of Facebook's social plug-ins, in which the button can be placed on third-party websites. Its use centers around a form of an advertising network, in which it gathers information about which users visit
Facebook were mobile users, 1.71 billion users in July 2016, 1.94 billion users in March 2017, and ultimately 2 billion users in June 2017. Early in 2015, it was reported that teenagers preferred competing web sites such as Instagram and Snapchat. The estimated number of teens leaving Facebook was a million per year. In November 2015, after skepticism about the accuracy of its "monthly active users" measurement, Facebook changed its definition of an "active user", now defining it as a logged-in member who visits the Facebook site through the web browser or mobile app, or uses the Facebook Messenger app, in