When the order defines the offer
Order-based incentives focus on the purchase as a whole. Order-value offers need a clear explanation of which parts of the order count, while product and collection campaigns connect the benefit to named merchandise.
When timing supplies the reason
A launch helps introduce a product; a seasonal campaign has a buying occasion and a defined window. Neither should confuse the date an order qualifies with the date the customer receives the benefit.
When the relationship continues after checkout
Post-purchase communication explains the benefit already associated with the order. A repeat-purchase program concerns a later qualifying purchase. Keeping those purposes separate avoids asking a customer to buy again just to understand the original reward.