Model the participation funnel
Estimate eligible Shopify orders, confirmed qualifications, successful customer communications, delivered incentives, expected use, and exception volume. Keep each assumption visible so actuals can replace forecasts.
Include operating costs
Consider provider charges, customer support, creative production, legal and compliance review, reconciliation, reporting, and internal ownership. Compare proposals on total program cost using the same volume assumptions.
Set decision boundaries
Define a maximum approved exposure, monitoring cadence, and the conditions for continuing, changing, pausing, or ending the campaign. Budget controls should be operational, not merely a spreadsheet target.