it could be concluded that you go to gambling sites only for bonuses and free prizes, I would say it is completely wrong. You attack them because they have reduced potential rewards and that is really just their goodwill, they can function without breaking any rules. it is not their obligation to give many rewards. You mess something there.
as much as I use gambling sites myself, Bitsler is one which offers the most opportunities to win free prizes and I have won enough myself.