According to a 2017 survey done by the National Association of Realtors, 51% of buyers found the home they purchased through the internet; that number has probably grown in the past few years.
Facebook is the de facto social networking site today, but you shouldn't forget about the rest of the sites, since their services are used by quite a lot of people as well. They are somewhat different from Facebook, so there are a few guidelines to consider when using them.