This is just staking $50 at odds of -200 or greater.
The bonus is paid out when the person you refer completes BetMGM’s registration and verification process, and then meets the easy to achieve wagering requirements.
This allows you to give a referral link to up to 20 people, giving both of you a $50 cash bonus. BetMGM has a referral bonus scheme called The More The Merrier.