It gets tiring, being asked by money-hungry hopefuls about ‘the most important’ network “for business” and on and on and on… LOOK! None of them are really about marketing, sales, or conversion (in general); that is an up-sell by the companies themselves and the many guru-types that abound but in all factual-basis, these networks are places for people to just waste time and decide on personal matters and tastes (vs. your great new idea).
Video-Games do well on social-media spheres because they are highly social-activities.
Same with Movies.
Music has taken a backseat because every time someone follows a new band etc., they get an immediate auto-generated message saying: “Hey, great to meet you, see me here, like me here, send your friends here.”
It has gotten beyond old for people.
So, in regards to Facebook (or any of the said networks), it’s essentially redistribution of your message and wares (more than it is communication) in most cases.