Retail media networks have become one of the fastest-growing segments in digital advertising. Retailers from Amazon to regional grocers now operate advertising businesses that leverage first-party shopper data to help brands reach consumers at or near the point of purchase. US advertisers spent $60.32 billion on retail media in 2025 and will spend $71.09 billion in 2026, according to a December 2025 EMARKETER forecast. This FAQ addresses how retail media works, who the major players are, and what marketers should consider when allocating budgets.

What is a retail media network?

A retail media network (RMN) is an advertising platform owned and operated by a retailer that allows brands to purchase ads appearing on the retailer's digital properties, physical stores, or partner channels. Amazon Ads, Walmart Connect, eBay, and Target Roundel are among the largest in the US.

RMNs differ from traditional digital advertising through their access to first-party purchase data. Retailers know what shoppers buy, browse, and add to carts, enabling targeting precision that third-party data cannot match. This data also powers closed-loop measurement, connecting ad impressions directly to transactions.

The channel continues rapid expansion. US retail media ad spending will grow 17.8% year-over-year in 2026, outpacing both social network and search ad spending growth rates, according to EMARKETER.

Why are advertisers investing in retail media networks?

Some 62% of CPG marketers expect to increase their retail media spending in the second half of 2025, per Mediaocean's 2025 H2 Market Report.

Four factors drive continued investment:

• First-party data access. As third-party cookies fade as a default solution, retailers' purchase data becomes increasingly valuable for targeting and personalization.
• Closed-loop measurement. RMNs connect ad impressions directly to transactions, providing deterministic attribution that traditional digital advertising cannot offer.
• Proximity to purchase. Ads reach consumers at or near the point of sale, reducing the gap between awareness and conversion.
• Full-funnel capabilities. 40% of advertisers regard retail media as capable of delivering full-funnel results, per August 2025 Infillion data. Only social media ranked higher at 52%.

How does retail media measurement work?

Retail media measurement relies on closed-loop attribution, which connects ad exposure to actual purchases using first-party transaction data. When a shopper sees an ad on an RMN and later buys the product, the retailer can link that impression to the sale.

This approach provides advertisers with metrics like return on ad spend (ROAS), incremental sales lift, and conversion rates tied to specific campaigns. However, measurement methodologies vary across platforms, making cross-retailer comparison difficult.

Standardization remains elusive. "Don't expect measurement relief any time soon," EMARKETER's November 2025 forecast warned. Some retailers have moved ahead independently. Albertsons Media Collective, for example, has standardized attribution rules internally, only counting conversions that occur after ad exposure. "If you saw it on the 14th and bought it on the 13th, we don't get credit," Evan Hovorka, VP of Product and Innovation, told EMARKETER.

What are the types of retail media ads?

Retail media ads fall into four main categories:

• On-site search ads. Sponsored product listings appearing in search results on retailer websites and apps. Search claims the majority of retail media spending and remains the entry point for most advertisers.
• On-site display ads. Banner ads, video units, and product carousels appearing on retailer-owned digital properties. Growth in this category is slowing as advertisers shift budgets off-site.
• Off-site ads. Ads powered by retailer data but served on external platforms like social networks, CTV, or the open web. 63% of the largest RMNs now offer off-site search capabilities, per Mars United Commerce's Q3 2025 Retail Media Report Card.
• In-store ads. Digital screens, audio, and interactive displays in physical retail locations. This category is scaling slowly despite high advertiser demand.

Which retail media networks have the largest market share?

Amazon Ads dominates the US retail media market with 79.7% share in 2025, according to EMARKETER. Walmart Connect ranks second with 8.0% share, more than five times larger than Target Roundel at 1.5%.

The gap is widening. Amazon and Walmart will capture 89% of incremental retail media spending in 2026, leaving a small slice for all other RMNs. The market share of every other RMN EMARKETER tracks will either stay flat or decline through 2027.

Commerce intermediaries are emerging as powerful media players, sitting between consumers and merchants and giving advertisers retailer-level results plus insight into cross-merchant purchase behavior. DoorDash and Instacart each generate close to $1 billion in annual US ad revenues, according to EMARKETER’s December 2025 forecast, competing for budgets historically directed to traditional RMNs. But these players have yet to prove they offer the incremental audiences or superior measurement that would compel advertisers to shift significant spend away from established RMNs.

What is driving retail media's expansion into CTV and offsite channels?

Advertisers' appetite for full-funnel campaigns is pushing retail media beyond retailer-owned websites. Social media and connected TV (CTV) now anchor off-site retail media strategies.

Social advertising accounts for nearly half of off-site retail media spending, per EMARKETER. Retail media CTV is growing rapidly as advertisers seek TV ads targeted using retailer first-party data.

Amazon holds a commanding lead in retail media CTV, thanks to Prime Video inventory and partnerships with Disney, Roku, and Netflix that feed its demand-side platform. Walmart is gaining ground after adding Vizio inventory to its DSP following its 2024 acquisition.

Some 72% of retail media advertisers say video is one of their main off-site spending areas, per Koddi and RetailX data. This demand is pushing more RMNs to build or partner for CTV and social capabilities.

What challenges do marketers face with retail media networks?

Despite rapid growth, retail media presents specific obstacles:

• Fragmentation. Each retailer operates its own platform with different ad formats, measurement standards, and buying interfaces. Managing campaigns across Amazon, Walmart, Target, and Instacart requires significant operational overhead.
• Limited transparency. Retailers control the data and often restrict visibility into performance metrics, audience composition, and incrementality.
• Measurement inconsistency. Attribution windows and methodologies vary across platforms. 86% of grocers report their retail media networks remain siloed from other marketing functions, per Grocery Doppio.
• Rising costs. As more brands compete for limited inventory, CPMs have increased, particularly for high-intent placements like sponsored search.
• In-store access. Approximately 1 in 4 ad buyers cite difficulty accessing in-store reach as a top challenge, per March 2025 Koddi data.

How are grocers and non-Amazon retailers competing in retail media?

Traditional retailers are leveraging their physical footprints and specialized audiences to differentiate from Amazon's digital dominance.

70% of grocery retailers plan to deploy in-store retail media within 18 months, per October 2024 Grocery Doppio data. This urgency reflects grocery's physical-first reality: 91.5% of food and beverage purchases still occur in stores.

Albertsons Media Collective is standardizing campaigns across Pinterest, DV360, The Trade Desk, and Meta, using consistent audiences and metrics across all activations. "Same audience, same methodology, everywhere," Hovorka told EMARKETER. The grocer employs LiveRamp's Habu clean room technology for secure data collaboration with advertisers.

Walmart's physical scale compounds its digital investments. Its US retail ecommerce sales are growing faster than any other major retailer EMARKETER tracks, and its off-site ad business now exceeds $1 billion annually.

How should marketers evaluate retail media network investments in 2026?

Due diligence should address four areas:

1. Audience alignment. Does the retailer's shopper base match your target consumer? Amazon skews broad; specialty retailers offer narrower but more relevant audiences. For CPG brands, grocers with high in-store traffic may deliver reach that digital-first RMNs cannot.
2. Measurement access. What reporting is available? Can you access impression-level data, or only aggregated summaries? Retailers that provide clean attribution and standardized metrics will reduce operational friction.
3. Incrementality testing. Does the platform support holdout testing or geo-experiments to measure true lift beyond baseline sales? With standardization unlikely soon, advertisers must push RMNs to prove audience incrementality.
4. Off-site capabilities. Evaluate the RMN's ability to extend campaigns to CTV, social, and the open web. Amazon and Walmart dominate off-site spending, but smaller RMNs with strong data collaboration tools can offer differentiated targeting.

Start with retailers where you have existing distribution and sales data to benchmark performance.

We prepared this article with the assistance of generative AI tools and stand behind its accuracy, quality, and originality.

EMARKETER forecast data was current at publication and may have changed. EMARKETER clients have access to up-to-date forecast data. To explore EMARKETER solutions, click here.