Email 1: within 30 min
'You left this behind.' Product images, one-click back to cart. No offer. Just reminder. 4-5% conversion here.
Email 2: 24 hours
Social proof — reviews, similar customer quotes. No offer yet. 1-2% incremental conversion.
Email 3: 72 hours
The incentive. 10% off with expiration. 1-2% more. Total 7-9% abandonment recovery for well-executed flows.