Retail media is the fastest-growing advertising channel in the world. Amazon generates over $50B in ad revenue annually. Walmart Connect, Kroger Precision Marketing, and Target's Roundel are scaling fast. Every major retailer is asking: can we build this too?
What a retail media network actually is
A retail media network (RMN) is an advertising platform built on a retailer's owned properties — website, app, email, in-store screens — powered by first-party shopper data. Advertisers (typically CPG brands) pay to reach your customers while they're in-market. The key differentiator is closed-loop attribution: you can prove that an ad led to a purchase.
The three things you need
To build an RMN, you need: (1) a first-party data asset — typically loyalty card data, email registrations, or purchase history; (2) owned advertising inventory — product listing pages, homepage banners, search results; (3) a self-serve platform or managed service for CPG brands to buy media. The data is the moat. The technology is the enabler.
Build vs. buy vs. partner
Most retailers start with a managed service partner (like Criteo, Epsilon, or CitrusAd) because they can launch quickly. But the economics of managed service erode margin. Our recommendation for retailers with $500M+ in annual GMV: build a hybrid — start with a partner to prove the model, then invest in proprietary infrastructure for the highest-value inventory.
The advertiser proposition
CPG brands will invest in your RMN if you offer three things: access to your first-party audience with demographic and purchase intent data; measurable ROAS with closed-loop purchase attribution; and competitive CPMs relative to Amazon and Walmart. If you can't deliver all three, launch is easy but retention will be hard.
What it takes to launch
Minimum viable: 3-4 ad formats (sponsored products, banner display, category takeover), a trafficking workflow, a reporting dashboard, and a direct sales team. Time to launch: 6-9 months with the right partner. Year-1 revenue expectation for a $2B retailer: $5-12M depending on CPG brand concentration in your category.