If you are thinking for going into gambling:
Me and my team switched to gambling 2 years ago since we found a nice way of getting traffic through BH marketing and the deals go from 100-200 eur CPA and solid revshare models from which you can build nice passive income if you do it right.
We currently work with iGamingGods. They offer us good hybrid CPA and RevShare deals and would gladly recommend them since I got a chance to meet them personally and are a nice team.
It works for us since we use BH methods to get traffic and their casinos support that.
There are also other providers, but it all depends on what would be your style of promoting, so I cant really direct right now.