Leave it in the basket

The mistake

An abandoned-basket recovery email fires on a rule that checks for items sitting in a basket, but the discount it issues escalates on each repeat send rather than being capped or issued once per basket. Because the incentive rewards the exact behaviour it measures, leaving the basket untouched pushes the offer higher, and there's no floor on the discount or check against margin. Turning the campaign off afterwards doesn't undo it — customers have already learned the waiting strategy, so demand at full price stays gone.