On a couple promo sites playMGM is rated a little of four stars. I’m assuming it’s higher not because of promos but software. The only promo for August I could find is a deposit bonus (deposit $100 receive $25 in free play). PlayMGM also has a couple progressive slots that have super high progressives, over $2 million.
Actually, the promo isn’t just for new deposits, it’s every Sunday for the month of August. They’re calling it “You Deposit We Bonus.” New casino bonuses seem to be a lot more lucrative so it’s probably a good one to take advantage of.