Costco retail media network: how Costco Velocity works and how to buy it

Every Costco shopper carries a card. Members must show it to buy, so Costco can tie each purchase, in a warehouse or online, to a household. Mark Williamson, who has led retail media since 2023, described this link in 2024 (Marketing Brew, 6 June 2024). Most retailers must match loyalty IDs to only part of their sales. Costco starts from a fully identified base of 84.1 million paid members.

The second difference is restraint. Costco says retail media must serve the member first. In May 2026 CFO Gary Millerchip said 80% to 90% of the value it creates is reinvested in members (Costco Q3 FY2026 call, 28 May 2026). He described personalisation as the first goal, with ads following it. Expect fewer placements than on a mass-market retail media network, and a buyer relationship that shapes what runs.

Third, Costco builds in public. In January 2026 Williamson showed the whole retail media technology stack on stage at an NRF event. MetaRouter acts as the identity and data layer and runs inside Costco's own private cloud. New vendors must integrate with it, under rules to own the data and limit copying (Retail Media Breakfast Club, 23 March 2026). A supplier can therefore ask exactly which system serves, targets and measures each ad.

The trade-off is narrow demand. A warehouse carries a curated range, so fewer brands can advertise. Williamson named that limited assortment as the "biggest constraint" on the business (Marketing Brew, 6 June 2024).

Onsite. Criteo powers sponsored product ads on Costco.com. Reserved Display, built with Moloco, adds personalised "digital end caps" on the homepage and in search results. Costco planned a beta with selected partners in the second quarter of 2026 and wider access later in the year (Supermarket News, 18 March 2026).

Offsite. Costco began with targeted campaigns on third-party sites. In fiscal 2025 Kimberly-Clark amplified a multi-vendor mailer, Costco's coupon book, with targeted digital ads that sent members back to product pages (Path to Purchase Institute, 1 October 2025). A Google Commerce Media and YouTube collaboration launched in fiscal Q3 2026. A deal with Symbiosys lets brands promote Costco products in Google Shopping, in beta since March 2026 (Mars United, April 2026). The offsite retail media explainer covers how such data flows work.

Print and in-store. Costco sells ads in its Costco Connection magazine. We found no public offer of in-store screens.

Targeting uses what members buy, their membership tier and their activity on Costco's digital properties. On the Q4 fiscal 2025 call Costco described homepage messages that differ for Costco Visa cardholders and other members (Path to Purchase Institute, 1 October 2025). Brands can build custom Costco audiences and use them in Reserved Display without extra steps.

Member data stays in Costco's environment. MetaRouter resolves signals to a member identity and passes them to activation tools without exporting raw records. Costco admits a gap: its tools long worked at visitor level, not member level, and the Moloco and MetaRouter work is meant to close it.

Moloco's engine optimises Reserved Display against actual sales rather than clicks. For Google Shopping campaigns, brands can track e-commerce sales in flight, with omnichannel attribution announced as the next step (Mars United, April 2026). Because the card links online exposure to warehouse purchases, closed-loop measurement is possible in principle.

Costco has not published an accreditation, an incrementality method or third-party verification. Its own north-star idea, that better ads raise membership renewal, is still unmeasured. Compare any report with the guidance in retail media measurement standards explained.

1. Start with your Costco buyer. Retail media sits close to merchandising. Raise media in the joint business plan you already have with Costco.
2. Run sponsored product ads first. They are the established onsite format and reach members who are already searching.
3. Ask for Reserved Display access. Costco planned to open it to all partners later in 2026 after a beta. Confirm placements, pricing and reporting before you commit.
4. Add offsite reach. Use the Google and YouTube collaboration or the Google Shopping programme if your brand already buys there.
5. Agree the measurement plan. Define the attribution window and whether warehouse sales are included. Ask which system in the stack produces each number.

It suits:

• suppliers with items already in Costco warehouses or on Costco.com;
• brands that want reach among higher-spending households;
• advertisers who value a clear view of the data and technology stack.

It suits less:

• brands that Costco does not stock, since ads promote items Costco sells;
• advertisers who want large volumes of self-serve inventory today;
• teams that need accredited metrics or an independent audit.

• Costco's retail media revenue for any period. Costco does not report it. The only figure we found is an analyst estimate of about $225 million in 2023 by BMO Capital Markets (Marketing Brew, 6 June 2024).
• Whether Reserved Display reached all partners by November 2026.
• Any minimum spend, rate card or self-serve sign-up page.
• Whether in-store media is sold.
• Launch dates for a clean room and programmatic access through external platforms.

1. Costco Wholesale, Q3 fiscal 2026 earnings call (28 May 2026), transcript by The Motley Fool. https://www.fool.com/earnings/call-transcripts/2026/05/28/costco-cost-q3-2026-earnings-transcript/
2. Costco Wholesale, Q4 fiscal 2026 earnings call (24 September 2026), transcript by The Motley Fool. https://www.fool.com/earnings/call-transcripts/2026/09/29/costco-cost-q4-2026-earnings-call-transcript/
3. Supermarket News, "Costco upgrades its retail media platform" (18 March 2026). https://www.supermarketnews.com/retail-media/costco-upgrades-its-retail-media-platform
4. Adweek, "Costco Adds Adtech Firm Moloco to Scale Retail Media Network" (18 March 2026). https://www.adweek.com/commerce/costco-adds-adtech-firm-moloco-to-scale-retail-media-network/
5. Retail Media Breakfast Club, "The 'Costco Velocity' Tech Stack Is Coming Together. Here's How the Pieces Fit." (23 March 2026). https://retailmediabreakfastclub.com/the-costco-velocity-tech-stack-is-coming-together-here-s-how-the-pieces-fit/
6. Mars United Commerce, "Retail Media Roundup: April 2026" (April 2026). https://www.marsunited.com/retail-media-roundup-april-2026/
7. Path to Purchase Institute, "Costco Signals New Era of Personalization, Retail Media" (1 October 2025). https://p2pi.com/costco-signals-new-era-personalization-retail-media
8. Marketing Brew, "Costco is building out an ad business using its shoppers' data" (6 June 2024). https://www.marketingbrew.com/stories/2024/06/06/costco-is-building-out-an-ad-business-using-shopper-data
9. Creative Magazine, "Costco Retail Media Partners With Moloco To Power Onsite Advertising Including AI-Powered Discovery At The Shelf" (27 May 2026). https://www.creativemag.com/?p=129501