You get sucky traffic if you target Audience Network and Tablets.<p>If you're targeting to a developing country, then you need to then filter by profession (e.g. Software Engineers, CTO, etc.). Some countries (notably Vietnam, Philippines, and Bangladesh) have fake account farms where they sell fake likes or do shady stuff like click on their clients' competitors' ads to they can jack up their cost.
I don't know if it's just FB or mobile users just suck for ads. I filter out mobile and tablet on google ads and get much better response.<p>Also, look into using re targeting when they are back on a desktop.