I still have a FB account since it's the only contact I have these days with a lot of my highschool friends. I logged in earlier today and saw this "NASA is a hoax" garbage in my "suggested" feed.
There's nothing in my history to suggest I have any interest in conspiracy theories. My friends are probably right-leaning on average (I'm from a small town in the south - so it goes), but I clicked and none of them are in that group. So I'm sort of assuming this is promoted. Joy.
I suppose that advertisers pick some parameters like geography, age, groups before starting the campaign.