Guide for CPA paid campaign

Need guide for paid CPA campaign. I can run facebook ads. what kind of offer should i promote which CPA platform should i choose? I tried to create accounts on maxbounty, crackrevenue but the didn't approved my accouts. Thank in advance.

What kind of offer would you feel more comfortable promoting? Gadgets? Software? Clothing? There's plenty of stuff to promote around, just choose what you like more.