Retail Media Networks Face Accountability and Growth Challenges

Retail media is experiencing a period of rapid expansion, yet advertisers are increasingly questioning the true impact of their spending as the industry lacks a consistent method for proving performance [1]. While many platforms report strong results, the reliance on varied attribution models has created a fragmented environment where it is difficult to distinguish between genuine growth and existing demand [1].

Key takeaways

• US retail media spend is projected to reach $69.33 billion by 2026, with Amazon and Walmart expected to capture over 89% of that growth [2].
• Advertisers are turning to incrementality—measuring the causal impact of ads compared to a control group—to determine if purchases would have occurred without advertising [1].
• Ghost ads, which use neutral placeholders in auctions to create valid control groups, are being adopted to improve the precision of lift studies [1].
• The IAB warns that many retail media networks face an "implicit sorting" by the market if they fail to make explicit strategic choices regarding their business models [2].

The Challenge of Proving Performance

The current retail media landscape is characterized by a "scale problem," where each network utilizes its own rules for attribution, lookback windows, and return on ad spend (ROAS) interpretations [1]. Because most measurement relies on crediting conversions to ad exposure, advertisers often struggle to identify whether an ad actually drove a sale or simply appeared to a shopper who was already planning to purchase [1]. This ambiguity makes it difficult to compare performance across different networks, as budget decisions are frequently based on inconsistent methodologies rather than objective outcomes [1].

To address these concerns, marketers are increasingly prioritizing incrementality, which isolates the true lift of a campaign by comparing outcomes between a group that sees an ad and a control group that does not [1]. Platforms like DoorDash have begun implementing "ghost ads"—a methodology that keeps control groups within the auction process to maintain natural dynamics—to provide more reliable data [1]. This approach has reportedly led to a 92% reduction in experimentation dilution and a 35% improvement in ROAS confidence intervals for the platform [1].

Strategic Choices in a Crowded Market

Beyond measurement, the industry is grappling with a saturation of retail media networks, as a database maintained by Mimbi currently tracks 270 networks worldwide [2]. With global market leaders expected to account for 57% of all sales growth between 2025 and 2030, many smaller networks are finding it difficult to compete for national brand budgets [2].

The IAB suggests that networks must move away from a default "scale-at-all-costs" mentality, which is often driven by unrealistic forecasts presented to boards [2]. Instead, the industry is seeing a shift toward more sustainable paths, such as treating media as a margin lever rather than a primary growth engine, or focusing on specialized, lean operations [2].