Monthly income could range from $0.10 to $10,000 (or more). If you happen to get lucky and have a track in a video that gets millions of views that’s thousands of dollars for you…
The track that generates the most money for me right now on AdRev has very few sales. Another track that earned me $1,000+ last year from AdRev has earned me less than $100 in license sales during its entire lifetime. It is now dead on AdRev because those videos aren’t getting many views anymore…
My most popular tracks that are licensed with hundreds of sales make very little money on AdRev. There is no correlation. Basically just luck. You never know.
You only need to use one service that registers with YouTube’s ContentID. You can’t also use the others since one is enough to get your tracks into YouTube’s system.