This may be a shock to you but there are other social media sites out there besides Facebook!  Facebook is still the largest by far but there are others.

Facebook 2,070,000,000
YouTube 1,500,000,000
Instagram 800,000,000
Twitter 330,000,000
Reddit 250,000,000
Pinterest 200,000,000
Vine (In January 2017, The Vine became the Vine Camera) 200,000,000
Ask.fm 160,000,000
Tumblr 115,000,000
Flickr 112,000,000
Google+ 111,000,000
LinkedIn 106,000,000
VK 97,000,000
ClassMates 57,000,000
Meetup 32,300,000