
They are basing this on GOOGLE SEARCHES and as they said, more and more people are using Facebook on their smartphones and are not searching for it on google
Facebook is not likely to be unpopular by 2017. I know younger people prefer the likes of Tumblr, Instagram & Twitter to Facebook, but I don't see any of those overtaking Facebook. Unless something else comes along and improves upon what Facebook did, like when Facebook crushed Myspace, then it isn't going anywhere anytime soon.