Expected Sportsbook % Commissions

If you are only talking about the sportsbooks that are worth promoting, I would assume the following is safe:

0-100 players = 30% MGR
100-250 players = 35% MGR
250+ players = 40% MGR

It’s very unlikely a book will offer more than 45%…even to their biggest affiliates. BetUS used to at one point, and then cut even their biggest affiliates back to 40%. Non-US books like Bet365 are even more stringent and that’s purely because of the amount of money they invest in offline branding. Usually the ones that convert best offer the lowest commission rates – even to their super affiliates.