Maybe one thing worth noting is that AdRev does also act as an (assisting) tool to remove videos, not just to monetize them. Once you become aware that a video is illegally using your music (thanks to their tracking and reporting), you will be able to get it removed if you choose rather than monetizing it. Its only a few simple steps to get it taken down completely. So there is a real threat for uploaders on that side too as their channels can be banned - even ones with tens of thousands of subscribers.
On the other hand, if it’s a known brand that is using your track illegally, download their video, document everything, and you now have a legal case against them worth much more than what AdRev would bring in. At the simple threat of a lawsuit they would be likely to settle with you for a lot more than the cost of licensing on AJ 
They would be in violation of your copyright and liabalbe for certain damages.
I won’t say how much I earn from AdRev, but just to give you an example, I have one song alone that has had over 5 million illegal plays in 6 months, so it’s not just all pennies over there.