Major delivery platforms to bring Costco to your door

Costco is expanding U.S. delivery nationwide through DoorDash and Uber Eats, enabling members to order groceries, household goods and electronics through both platforms. The rollout gives DoorDash its first U.S. same-day Costco delivery offering and expands Uber Eats beyond its prior 17-state Costco footprint. The partnerships broaden Costco's convenience proposition for its roughly 125 million global members and increase competitive pressure on Instacart, which has handled Costco grocery orders for nearly a decade.

Analysis

The economic value is likely greater for DASH and UBER than for COST in the near term: Costco’s low gross-margin model leaves limited room to subsidize delivery, while the platforms gain high-frequency grocery/household order occasions, basket data, and potential membership-adjacent retention. The key underwriting question is whether Costco orders are incremental to platform demand or merely cannibalize Instacart volume; if incremental, grocery mix should improve order density and courier utilization, supporting contribution margins even if take rates are discounted.

COST’s strategic benefit is convenience-led renewal protection among younger, urban, and time-constrained households, but same-day fulfillment can dilute the treasure-hunt warehouse experience and shift mix toward bulky, low-margin staples. The more material 6-18 month implication is negotiating leverage: a multi-platform model weakens CART’s historic exclusivity/value proposition and could force greater promotional spending or lower retailer economics to defend grocery share. CART is more exposed than the two incumbents because it lacks the same ride-hailing or restaurant-demand base to absorb retailer-specific margin pressure.

Consensus may overstate the immediate revenue contribution for DASH/UBER. Costco members are unusually price sensitive and may resist delivery fees, tips, and platform-marked-up SKUs; the proof point is repeat purchase frequency, not launch-period gross order value. Watch quarterly grocery GTV growth, Costco-order average basket versus platform average, and adjusted EBITDA margin commentary: sustained grocery growth without a sequential margin giveback would validate the density thesis within 1-3 quarters.

Key Decisions for Investors

• Maintain/establish a 3-6 month long DASH / short CART pair: DASH has the cleaner incremental-demand and density upside, while CART faces higher retailer disintermediation risk. Reassess if CART shows accelerating enterprise retailer additions or DASH’s adjusted EBITDA margin declines sequentially despite grocery GTV growth.
• Prefer UBER over COST for a tactical 1-3 month expression: the partnership reinforces Uber Eats’ grocery credibility, but size modestly because delivery economics are unproven. Take profits if the stock rerates without disclosed grocery-order or delivery-margin evidence.
• Do not chase COST on this development alone. Treat it as a retention/renewal optionality catalyst rather than an earnings driver; upgrade only if management identifies delivery as incremental membership acquisition or demonstrates no measurable gross-margin dilution.
• Set an earnings watch on CART: a meaningful increase in incentives, lower take rate, or commentary on Costco volume pressure would support adding to the short leg; stable gross transaction value and margin despite the loss of exclusivity would falsify the thesis.