Choose stable identifiers
Document whether eligibility follows specific products, variants, or collection membership at a defined point in time. Avoid relying only on page titles or merchandising labels that can change during the campaign.
Handle mixed baskets
Explain how qualifying and non-qualifying items interact, whether quantities matter, and what occurs when part of the basket is returned. Customers should not need to infer the calculation.
Coordinate merchandising and operations
Campaign owners, catalog teams, support, and reporting should share a versioned scope. Additions or removals need an effective time and a review of customer-facing terms.