If you go to the Vegas strip, you can find some very bad rake structures out there. These card rooms are just as full as ones with better rake structure. Same with a Blackjack game. Minor rule changes increase the casino profit by a few % and the average player doesn't notice. Don't decrease rake, increase rakeback. It will have the same effect as a tax return at the end of the year. Make it automatic and advertise it as cashback for playing every month.