Let me have some input from here.
Bonuses has various types. And I highly believe that the OP is not looking for faucets (which is most of the time, completely free). The OP is asking about casino that has good % bonuses, and lower RTP (he mentioned it).

Somehow, these bonuses (rakeback, daily, monthly rewards, etc.) are really helpful as you can make something happen from it. I had few experience in which I turned some bucks I got from my monthly into a $1k.