The warehouse club is buying digital reach with somebody else's courier network while keeping the membership relationship and avoiding single-platform dependence.
Costco has added DoorDash delivery from all US warehouse locations while Uber expands its Costco service across 47 states. Instacart already carries Costco inventory, leaving the retailer deliberately spread across several last-mile networks.
That makes the strategic allocation clearer than the unit economics. Costco keeps the warehouse as the inventory and fulfillment node, keeps the membership relationship, and lets delivery platforms provide variable-cost courier capacity. It can add convenience without buying a national fleet or building a separate e-commerce distribution system.
DoorDash said US customers must link a Costco membership to shop the retailer through its platform. That detail matters because the highest-value relationship stays with Costco even when the order originates in another app.
For DoorDash and Uber, access to Costco adds a recognizable merchant and potentially large baskets to their push beyond restaurants. The limitation is exclusivity: neither platform can treat the retailer as proprietary inventory when the same member can reach Costco through rival networks.
The missing numbers are the ones that would support a stronger profit conclusion. The companies have not disclosed platform take rates, promotional funding, delivery subsidies or Costco's incremental margin on a same-day order. Without them, it is impossible to say which delivery partner has the better unit economics or how much the rollout adds to Costco earnings.
The strategically useful conclusion is narrower. Costco has expanded digital distribution without taking on the fixed cost of the last mile and without handing one platform control of member access. DoorDash and Uber gain volume; Costco preserves optionality.
Sources
- Associated Press, "DoorDash and Uber Eats to offer delivery from US Costco stores," September 17: https://apnews.com/article/e6f030d67dfc34fad737282c108ed929
- DoorDash, Costco partnership announcement: https://about.doordash.com/en-us/news/doordash-costco-partnership
- Uber, Costco nationwide delivery expansion, September 16: https://investor.uber.com/news-events/news/press-release-details/2026/Costco-Expands-Nationwide-Delivery-on-Uber-Eats/default.aspx