In my experience, facebook is for marketing ( getting your name out). Google is for results ( We had a facebook page with Pokémon Go, where we had 6 events in theme parks. We did it all with facebook and a website... None the less, i seriously changed my opinion about Facebook considering ads. It's not worth it ) We had a reach of 320.000 people with only 100$ spend on ads ( because of the hype it was really cheap an…
If a conversion isn't worth $0.33 to you, I would recommend re-examining your pricing structure and perhaps even model.
I may have misunderstood what you said, in which case I apologize. My point is not to criticize your effort, or deny your experience, but to correct a perspective I see a lot.
Don't worry about the number of impressions. Focus on how many customers you can get, then back out the numbers to find out how much revenue that made you.