Duo is a Shopify App that boosts e-commerce sales by harnessing the power of group shopping. It introduces a unique cashback system designed for two: when a customer makes a purchase, they receive a referral link specific to the store. If a friend uses this link to buy within 48 hours, both receive a cashback reward, with the percentage set by the retailer. Duo transforms e-shopping into a shared experience, driving engagement and increasing conversions.