I have not been able to make money with regular FB ads.
I have been able to make money on Facebook with remarketing. (Remarketing is showing adds selectively to people who have visited your site or taken a particular action on your site.)
I get great ROI from remarketing on Google, Bing and FB. I haven't tried other platforms.
Since you can only remarket/retarget your own visitors your volume will be low, but it may give you better ROI than anything else you do.
Remarketing - That sounds like a solid tip. I'm going to have to look into that.
Thanks!