DoorDash has spent the last several years moving beyond delivery and deeper into the restaurant’s four walls, adding products across reservations, payments, advertising, and loyalty. Its new In-Store Rewards program might be one of the sneakier extensions of that strategy. Restaurants can now offer DoorDash users rewards for dining in-store, giving operators what looks like another performance marketing channel to drive traffic. But, as HNGRY recently discovered, the mechanics create a much more interesting arbitrage: DoorDash can use linked credit cards to identify customers who were already eating at a restaurant, encourage them to claim a discount on their next visit, make the merchant fund the full value of that reward plus a fee, and then issue the reward as DoorDash credit that gets spent back inside its own marketplace. The platform is effectively turning existing restaurant demand and contribution margin into fuel for its own growth.