Retail Media Networks (RMN): 2026 US Benchmarks
Retail Media Networks (RMN): 2026 US Benchmarks
Why elite US brands are abandoning ROAS for TACoS on Amazon and Walmart Connect.
What is the average ROAS for Retail Media Networks like Amazon and Walmart in the US in 2026?
In 2026, the US average ROAS for Amazon Ads hovers around 3.1x (with an ACoS of ~32%), while Walmart Connect shows higher volatility as it scales its inventory. However, comparing ROAS directly between Retail Media Networks (RMNs) is a critical error. Each network uses proprietary 'closed-loop' attribution methodologies designed to maximize their own reported performance, leading to heavy cross-channel duplication. Because of this, advanced US advertisers have largely abandoned platform-reported ROAS. Instead, they measure success using TACoS (Total Advertising Cost of Sales)—evaluating total ad spend across all RMNs against total overall gross revenue to ensure that the ad spend is actually driving incremental, profitable growth at the SKU level.
Retail Media Networks (RMNs) represent the third great wave of US digital advertising, following Search (Google) and Social (Meta).
As third-party cookies died, retailers like Amazon, Walmart, and Target realized they sat on the most valuable first-party data in the world: actual point-of-sale purchase history. In 2026, if you are a CPG or E-commerce brand, you are forced to "pay to play" on these networks to secure digital shelf space.
The ROAS Illusion
The primary selling point of RMNs is "closed-loop attribution"—the ability to definitively tie an ad click to a purchase within the same ecosystem.
However, this closed loop is heavily biased. If a user clicks a Meta Ad, then clicks a Google Search Ad, and finally clicks an Amazon Sponsored Product Ad before buying, Amazon takes 100% of the credit in its dashboard. This leads to wildly inflated ROAS reporting across all RMNs.
| RMN Ecosystem (US) | 2026 Focus | Performance Reality |
|---|---|---|
| Amazon Ads | Efficiency & Profitability | Mature market. Rising CPCs (~$1.22+). Focus is on SKU-level discipline. |
| Walmart Connect | Scale & Market Share | Aggressive expansion. Brands are paying higher CPCs to capture new demand. |
Status
The Shift to TACoS
- ACoS (Advertising Cost of Sales)Ad Spend ÷ Ad Revenue
- TACoS (Total Advertising Cost of Sales)Ad Spend ÷ Total Revenue
Recommendation:Do not optimize your RMN budgets using ROAS or ACoS. Because these metrics only measure revenue that the platform claims credit for, they incentivize overspending on branded search terms (users who were going to buy anyway). You must optimize for TACoS. By measuring total ad spend against total overall sales, you can determine if your advertising is actually lifting the baseline revenue of your business.
Incrementality Testing: The only way to prove that your Amazon or Walmart ad spend is not cannibalizing your organic sales is to run deliberate 'Dark Periods.' Turn off all branded search spending on the RMN for 14 days and monitor the drop in total SKU velocity. Often, organic rankings absorb the traffic, proving the ad spend was wasted.
Off-Site Traffic and Creative Testing
To combat rising CPCs within the Amazon ecosystem, elite US brands are utilizing "Off-Site" traffic strategies. By running Meta or TikTok ads that link directly to their Amazon storefront (often using the Amazon Attribution program), brands can drive cheaper external traffic to boost their organic Amazon BSR (Best Sellers Rank).
However, this strategy requires a massive volume of social creative to keep CAC low.
This is where programmatic assembly tools like eonikbecome a competitive advantage. By allowing brands to instantly generate dozens of social ad variations tailored for Amazon-specific offers (e.g., "Prime Day Deal" overlays), eonik ensures that the brand can profitably funnel cheap, high-intent social traffic into the RMN ecosystem, outmaneuvering competitors who rely solely on expensive internal Amazon Sponsored Ads.
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