The Retail Media Ecosystem Explained: Components, Players, and Why Everyone Wants In
Most explainers on retail media describe what it is and call it a day. This one goes further: who’s actually in the room, what each player wants, and why the whole thing works when it works.
Retail media is one of those terms that gets thrown around in planning meetings by people who have slightly different definitions of it in their heads and nobody stops to compare notes.
So before the strategy conversation: what is it, who builds it, who buys it, and what does each party actually get out of it.
The short version
A retailer has customers. Those customers have purchase histories, browsing behavior, basket data, loyalty card activity. That data is valuable, extremely valuable, to the brands whose products those customers buy or might buy.
Retail media is the business of a retailer monetizing that data, a model that sits at the core of modern retail media advertising and adtech evolution, by selling advertising to brands, letting them target those customers with ads that appear across the retailer’s owned properties and increasingly across external channels too.
Amazon built the template. Now 277 retailers globally are running some version of the same model, forming a rapidly expanding landscape of retail media networks.
The global retail media market hit $140 billion in 2024, reflecting the accelerating future of retail media. It’s projected to reach $165 billion by the end of 2026. For context, it’s growing faster than the total digital ad market and is on track to account for a quarter of all US ad spend by 2028.
That’s the short version. Now for the parts that actually matter.
The components: what the ecosystem is actually made of
On-site inventory
This is where most people’s mental image often shaped by early exposure to retail media network platforms. of retail media begins and ends. Sponsored product listings on Amazon. Promoted placements on Walmart’s search results. Banner ads on a retailer’s homepage.
On-site is the foundation because it captures buyers at the sharpest point of intent: they’re already on the platform, already searching the category, already in purchase mode. The brand pays to show up at the exact right moment.
Sponsored product ads alone are projected to account for $38 billion in advertiser spend in 2026. For most brands, it’s the entry point into retail media and often the highest-performing format in the mix.
The limitation is ceiling. On-site inventory is finite. There are only so many sponsored slots on a search results page, and as more brands compete for them, CPCs rise and efficiency tightens.
Off-site inventory
This is where the ecosystem opened up. The data doesn’t have to stay on the retailer’s platform.
Off-site retail media uses a retailer’s first-party shopper data, extending into environments similar to modern social media marketing ecosystems. to target those same shoppers on external publisher sites, social platforms, programmatic display, and connected TV. The retailer’s audience, everywhere else they go online.
It’s why Amazon DSP is a meaningful product independent of Amazon’s own pages. It’s why Walmart Connect can reach Walmart shoppers on third-party inventory. The data travels; the real estate doesn’t have to be owned.
Over 20% of US retail media spend now goes to off-site channels, aligning closely with cross-media advertising strategies. Amazon DSP advertisers grew spend 31% year over year in Q4 2025 as impressions climbed 32%.
In-store
The most underinvested component for most brands, despite its importance in the evolving future of retail media networks. and the one catching up fastest.
Digital screens at the endcap. Checkout lane displays. Store-mode features in retailer apps that serve offers based on what’s physically around the shopper. Audio in the aisles. Scan-and-go integrations that serve a competing brand’s ad the moment you scan their competitor into your basket.
80% of consumer spending still happens in physical stores. The retail media ecosystem is finally building the infrastructure to monetize that attention the same way it monetizes digital.
The data and measurement layer
This is the component that makes the whole thing worth anything: closed-loop measurement.
A brand runs a sponsored product campaign. A customer clicks, or doesn’t. A purchase happens, or doesn’t. The retailer knows, because the purchase happens on their platform or through their loyalty system. The attribution loop closes.
No other advertising channel has this by default. Google knows if someone clicked. It doesn’t know if they then went and bought the product in-store three days later. Retail media does, or can, which is why the ROI case for brands is structurally stronger than almost anything else in the media mix.
The catch: every retailer runs their own attribution model, their own definition of conversion, their own reporting format. Comparing ROAS across four different networks is still a manual exercise that requires reconciling fundamentally different methodologies. It’s the biggest infrastructure problem in the space.
The players: who is actually in this ecosystem
The retailers
The retailers are the asset owners. They have the data, the inventory, and the customer relationships.
Amazon sits at the top with $60 billion in ad revenue in 2025 and roughly 75% of the US retail media market by some measures. Walmart Connect is the fastest-growing major network. Target’s Roundel, Kroger Precision Marketing, CVS Media Exchange, Instacart Ads, Home Depot’s Orange Apron Media, each one is a distinct network with its own audience, its own data set, and its own ad tech stack.
What’s changing in 2026 is the mid-market. Smaller retailers who can’t build proprietary ad tech are licensing Amazon’s Retail Ad Service or partnering with platform providers to stand up competitive networks. The ecosystem is decentralizing faster than most brands have adjusted for.
The brands and advertisers
For brands, retail media sits at an awkward intersection similar to how budgets are split across B2B media partnerships and digital channels. of trade marketing and brand marketing budgets. Historically, money spent at the retailer level came from trade. But off-site CTV campaigns using Kroger data? That’s a brand media buy.
Most large CPG brands now allocate 39% of total advertising spend to retail media. The ones getting strong returns are running it as a performance channel with real incrementality testing, not just renewing sponsored product budgets because they always have.
The ones getting mediocre returns are treating the network’s self-serve dashboard as the strategy.
The technology layer
Behind every retailer’s network is an ad tech stack similar to infrastructures discussed in retail media adtech ecosystems, demand-side platforms, supply-side platforms, data clean rooms, measurement and attribution tools, and creative optimization systems.
Some retailers built their own. Most are assembling from vendors: The Trade Desk, LiveRamp, Epsilon, Criteo, CitrusAd, Quotient. Data clean rooms have become the infrastructure, especially as privacy concerns grow alongside synthetic media and deepfake technologies. for brands and retailers to collaborate on audience data without the retailer handing over raw customer records, which they won’t and legally often can’t.
Only 12% of commerce media decision-makers describe themselves as having reached an advanced state with full-funnel capabilities across on-site, off-site, and in-store. The tech exists. The integration is the hard part.
The agencies
Agencies occupy an awkward position as responsibilities overlap with modern media buying processes. in the retail media ecosystem. Retail media buying historically happened through retail or shopper marketing teams. Digital media buying happened through media agencies. They were separate workflows with separate briefs and separate relationships.
Retail media collapsed that division. requiring integration similar to cross-media ad strategies. A brand now needs someone who understands Amazon’s auction mechanics, Walmart’s audience segments, programmatic DSP buying, and CTV creative requirements, simultaneously. The agencies that built that capability are worth a lot right now. The ones that haven’t are billing for it anyway.
The benefits: what each player actually gets
For retailers: the margin business they always needed
Core retail is a margin-thin business. making diversification into retail media advertising models essential. Grocery runs at 1% to 3% net margin on a good year. Retail media generates 50% to 70% operating margins on ad revenue.
That’s not a side business. For retailers operating at scale, media revenue is becoming a meaningful offset to the structural cost pressures in their core operations. Walmart’s media and data business is a strategic asset in a way their apparel category will never be.
For brands: the data they can’t get anywhere else
What brands are actually buying are often tied closely to data-driven lead generation services. When they buy retail media, it is not impressions. It’s access to purchase data.
Behavioral targeting on social is based on inference: this person liked three fitness posts, so they might buy protein supplements. Retail media targeting is based on purchase history: this person bought protein supplements from this retailer twice in the last 60 days. One is a guess. The other is a record.
For brands trying to reach buyers at the moment of highest commercial intent, and measure whether the ad actually drove a sale, retail media is the sharpest tool available.
For the shopper: relevance instead of noise
This one gets skipped in most ecosystem explainers, but it matters.
When retail media works as it should, similar to effective social media marketing strategies. the shopper sees ads for products genuinely relevant to what they buy, when they’re already thinking about buying. That’s a different experience from a retargeted ad following someone around the internet for a product they bought three weeks ago.
The ecosystem earns consumer tolerance by being useful. The moment it tips into surveillance-feeling or repetitive, that tolerance disappears fast.
Where the ecosystem goes from here
The three pressure points that will shape retail media through 2026 and beyond are measurement standardization, off-site scale, and consolidation.
Measurement first. The IAB has pushed for standards. Individual networks have their own incentives to keep methodologies proprietary. Until a brand can compare incremental ROAS across Amazon, Walmart, and Kroger in a consistent format, the budget allocation decisions happening inside brands will keep being made on incomplete information.
Off-site second. The ceiling on on-site inventory is real. The networks that figure out how to extend their first-party data into premium off-site environments, CTV especially, will hold advertiser budgets through the next phase. The ones that stay purely on-site will commoditize.
Consolidation third. 277 retail media networks is not a stable number. Most of them lack the scale, the data infrastructure, and the advertiser relationships to compete long term. The market will concentrate. The question is whether it concentrates around retailers or around the ad tech layer that retailers increasingly depend on.
The ecosystem is not finished being built. That’s either a problem or an opportunity, depending entirely on which side of the budget you’re sitting on.
