Swap functionality lets subscribers change products in their upcoming delivery without canceling or skipping. This is especially valuable for brands with multiple SKUs. Use cases: - Try different flavors or varieties - Adjust for seasonal preferences - Respond to inventory needs - Accommodate changing tastes Implementation tips: - Set swap deadlines before processing - Show only in-stock options - Allow partial swaps (some items) - Maintain price parity or handle upgrades - Track swap patterns for insights