Retail media ad spend crossed $67 billion in the U.S. last year, according to eMarketer’s Q1 2026 Retail Media Forecast — and the split between Amazon Ads and Walmart Connect is no longer as lopsided as it once was. Walmart Connect posted 38% year-over-year growth in Q4 2025, driven by its expanded off-site network and the rollout of in-store digital display units in 4,600 locations. For operators running six- to eight-figure catalogs, ignoring one platform means leaving measurable revenue on the table.
The problem is that most brands still treat the two networks as parallel universes — separate agency teams, separate budgets, separate reporting stacks. That siloed approach is killing efficiency. The brands gaining share in 2026 are running unified retail media frameworks: shared creative assets, cross-platform keyword intelligence, and attribution models that treat Amazon and Walmart as complementary, not competing, demand channels.
Here is an operational step-by-step guide for building that unified strategy from scratch.
Step 1: How Do You Audit Your Current Retail Media Baseline?
Before you touch a single bid, you need a clean baseline. Pull the last 90 days of performance data from both Amazon Ads Console and Walmart Connect’s campaign dashboard. You’re looking for three numbers: total ad spend by platform, blended ROAS by campaign type, and new-to-brand (NTB) customer rate.
Most operators are shocked at this stage. The average brand audited by retail media consultancy Acadia in early 2026 was running an effective ROAS of 3.1x on Amazon Sponsored Products but only 1.7x on Walmart Sponsored Products — not because Walmart’s inventory is weaker, but because bids were imported directly from Amazon without Walmart-specific demand modeling.
“The number-one mistake we see is brands using Amazon ACOS targets as a proxy for Walmart. The two platforms have fundamentally different shopper intent curves at the category level. You cannot copy-paste.” — Jess Huang, VP of Retail Media Strategy at Acadia
Your audit checklist:
- Export campaign-level ACOS and ROAS for Sponsored Products, Sponsored Brands, and Sponsored Display on Amazon
- Pull equivalent data from Walmart Connect for Sponsored Products and Search Brand Amplifier
- Tag each campaign by funnel stage: awareness, consideration, conversion
- Flag any campaigns running without negative keyword lists — these are your biggest waste pools
- Identify your top 20 SKUs by organic rank on each platform; these should anchor your paid strategy
Step 2: How Do You Build a Cross-Platform Keyword Intelligence Layer?
Keyword strategy on Amazon and Walmart diverges more than most operators realize. Amazon’s A9 algorithm is mature and heavily weighted toward conversion velocity and review count. Walmart’s algorithm, rebuilt on its Luminate data stack, places greater weight on in-store purchase history and loyalty data from Walmart+ members, who now number 48 million subscribers as of May 2026.
The practical implication: high-volume, high-competition keywords on Amazon don’t automatically translate to Walmart. Category-specific modifier terms — “value size,
