In 11 of its 23 states, BetMGM's sign-up offer is: New Indiana customers: up to $1,500 in bonus bets on first bet. Promonyx estimates it is worth $675, and it needs about $3,750 available at once. Use code BETMGMBONUS at sign-up, as BetMGM lists it on its own site.
BetMGM's offer is checked in 23 states: Arizona, Washington DC, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Missouri, Mississippi, North Carolina, New Jersey, Nevada, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, Wyoming. 4 state groups get a different offer, listed below.
Your first bet is covered. If it loses, the book refunds the stake as bonus bets, up to the limit. If it wins, you keep the winnings and get nothing extra. What it is worth depends on how much you bet and what the refund is worth once it lands.
About $675 on $3,750 of cash needed at once, a 18% return. That is an estimate of the offer before it is placed, based on the book's terms and prices at the time.