I know what am talking about I tried it for 3 years straight and definitely had to kick the habit as advertising with facebook has become extremely toxic to my bank account with dozens of withdrawals and not one single deposit from marketing and marketing on social media with facebook being the worst offender of them all.
Sure, I received thousand of clicks that cost me anywhere from $0.003 per click to $2.50 per click. My greatest peeve was the fact that for some reason it seems that if you are living outside the US it's virtually impossible to optimise your ad to receive USA traffic and if you do it will cost you a very affordable $2.00 per engagement - grrrrrrr8!!!
Another shitty experience goes like this: I optimise my ads for traffic to be generated from USA, UK, Canada and Australia but for some reason by some algorithm your ad is reset to receive traffic from Zarzerbania, African Sahara and the Pigmy Islands in the South Pacific.
So my educated conclusion is that FaceBook is unfriendly to advertisers who are not based in the USA and other so-called "tier 1" countries.