Contribution margin is what is left after subtracting redemption and processing cost from collected fees and add-ons. It is the real margin the membership produces, not just the fee members pay.

Incremental profit goes one step further: it subtracts what those same members would likely have spent, and cost you to serve, without a membership at all. A membership priced too close to your pay-per-visit price, with most visits already happening anyway, can show healthy collected revenue and still add little real profit.

This is an illustrative model, not accounting or tax advice. Real economics depend on your own costs, churn, and failed payments.