Walmart Connect vs. Amazon DSP in 2026: Which Retail Media Network Wins?

Retail media advertising has quietly become the most contested budget line in ecommerce marketing. By Q1 2026, U.S. retail media ad spend crossed $61.4 billion annually, according to eMarketer’s March 2026 forecast — with Amazon capturing roughly 75% of that total and Walmart’s Connect platform accelerating fast in the remaining share. For Shopify-to-marketplace operators, DTC brands expanding onto retail shelves, and agency leads managing eight-figure ad budgets, the question is no longer whether to invest in retail media. It’s which network delivers the better return.

This comparison puts Walmart Connect and Amazon DSP head-to-head across the metrics that matter most: audience scale, first-party data quality, CPMs, off-platform reach, attribution accuracy, and minimum spend thresholds. The answer, as usual, is more nuanced than either platform’s sales team will tell you.

How Does Each Platform’s First-Party Data Actually Stack Up?

Amazon’s first-party data advantage is almost unfair. With 230+ million active U.S. Prime members and 13+ years of purchase intent signals across 500 million product SKUs, Amazon DSP can target audiences by purchase history, brand affinity, product category, and even competitor shopper behavior with a precision no other retail network has matched at scale. The platform’s AMC (Amazon Marketing Cloud) clean room layer, now running on AWS Infrastructure as of late 2025, allows advertisers to build custom audience cohorts from first-party signals and CRM uploads — a capability that moves DSP from “walled garden” into something closer to a full data management platform.

Walmart Connect’s pitch is different but increasingly credible. Walmart serves 255 million weekly global shoppers, including 90 million weekly U.S. store visitors — offline purchase data that Amazon simply cannot replicate. That in-store behavioral signal is Walmart Connect’s genuine differentiator. A customer who buys Tide pods every three weeks at a physical Walmart location represents a purchase intent pattern that digital-only purchase data misses entirely.

“The Walmart in-store signal is underappreciated. We ran a CPG campaign in Q4 2025 where in-store purchase audience segments outperformed pure digital lookalikes by 34% on ROAS. That’s data you can’t get from a pure-play ecommerce network.” — Lauren Kretz, VP of Commerce Media, Tinuiti

💡 Article Summary

Key Insights

1

How Does Each Platform’s First-Party Data Actually Stack Up?

2

What Are the Real CPM Benchmarks and Minimum Spend Thresholds?

3

How Does Off-Platform Reach Compare Between the Two Networks?

4

How Does Attribution Work — and Where Does It Break?

5

Which Platform Performs Better by Category?

Source: Ecommerce Times

Amazon’s data depth still wins for most categories. But for CPG, grocery, household, and health brands with meaningful brick-and-mortar velocity, Walmart’s omnichannel signal is genuinely superior.

What Are the Real CPM Benchmarks and Minimum Spend Thresholds?

Cost structures remain one of the most cited barriers to Walmart Connect adoption among mid-market sellers. Here’s what operators reported in Q1 2026:

• Amazon DSP CPMs: $8–$18 for standard display; $15–$35 for video; $25–$55 for OTT/streaming TV (Prime Video placements post-ad tier launch)
• Walmart Connect CPMs: $6–$14 for on-site display; $10–$28 for offsite programmatic; $20–$45 for in-store digital display (Walmart’s physical screen network)
• Amazon DSP minimum spend: $50,000 managed service; self-serve via Amazon Ads console available at lower thresholds for some ad types
• Walmart Connect minimum spend: $25,000 for managed campaigns; self-serve DSP now accessible at $5,000/month following a November 2025 platform update

The minimum spend gap has narrowed considerably. Walmart’s self-serve DSP expansion — announced at its Commerce+ summit in November 2025 — opened the platform to brands spending $5K/month, which effectively tripled the addressable seller base overnight. Amazon’s managed DSP remains a $50K+ entry point, though the line between DSP and Sponsored Products is increasingly blurred for sellers already running aggressive keyword campaigns.

“Walmart lowering the self-serve DSP floor to five thousand dollars was the most important retail media pricing move of 2025. It pulled in an entirely new tier of seller — brands doing $2M to $10M in Walmart revenue who couldn’t justify a managed spend commitment before.” — Jason Roussos, GM of Retail Media, ChannelAdvisor

How Does Off-Platform Reach Compare Between the Two Networks?

Both platforms have aggressively expanded their off-platform (offsite) programmatic capabilities, but with different infrastructure and inventory quality.

Amazon DSP’s offsite reach runs through Amazon’s own supply-side platform, which accesses premium publisher inventory via deals with major SSPs including Magnite and Index Exchange, plus Amazon’s owned properties (Twitch, IMDb TV, Freevee). The addition of Prime Video ad inventory — which became available at scale in January 2025 after Amazon’s ad-supported tier hit 115 million monthly U.S. viewers — gave DSP a streaming TV pipe that rivals Roku and YouTube in authenticated household targeting.

Walmart Connect’s offsite programmatic runs through a rebuilt DSP layer powered by The Trade Desk partnership, which Walmart deepened in early 2025. This means Walmart Connect buyers get Trade Desk’s premium open-web inventory reach — roughly 600+ billion daily bid requests — married to Walmart’s first-party retail data. The Trade Desk integration gives Walmart Connect a credible response to Amazon’s owned inventory advantage by prioritizing reach breadth over depth.

• Amazon DSP off-platform strength: Authenticated streaming TV, owned O&O inventory, strong in-flight purchase signal for retargeting
• Walmart Connect off-platform strength: Trade Desk-powered open web scale, strong CTV through Vizio SmartCast (owned by Walmart since 2023), improving cross-device match rates

Vizio’s 18 million SmartCast active accounts give Walmart Connect a CTV asset that is often overlooked. For brands trying to reach cord-cutters who shop in physical Walmart stores, that SmartCast + in-store purchase combination is a genuinely differentiated targeting layer.

How Does Attribution Work — and Where Does It Break?

Attribution remains the messiest part of retail media for operators. Both platforms measure on their own terms, with limited third-party verification.

Amazon DSP offers 14-day click, 14-day view-through, and 1-day view-through attribution windows. AMC’s SQL-based clean room allows path-to-purchase analysis across DSP, Sponsored Products, and organic search — a significant improvement over the old last-click model. But AMC still requires meaningful technical lift to use properly, and third-party measurement via MTA providers like Northbeam or Rockerbox remains incomplete because Amazon doesn’t pass impression-level data outside its walls.

Walmart Connect’s attribution model is less mature but improving. The platform supports 14-day click and 3-day view-through attribution, and its Walmart Luminate data platform — which launched to advertisers in 2024 — now allows brands to cross-reference ad exposure with in-store and online purchase data in near-real time. Independent measurement via IRI/Circana integration went live in Q3 2025 for CPG advertisers, which gives Walmart Connect a credible third-party verification path that Amazon still lacks.

“Amazon’s AMC is genuinely powerful if you have the analyst resources to run custom SQL queries. But for most mid-market brands, Walmart’s Circana integration is more immediately usable — you get a clean sales lift study without a data science team.” — Marcus Webb, Director of Performance Media, Orca Pacific

Which Platform Performs Better by Category?

The honest answer depends heavily on where your brand sells and what consumer behavior patterns drive your category. Based on agency and merchant reporting through Q1 2026:

• Amazon DSP wins for: Electronics, books, toys, home goods, beauty, apparel, and any category where online purchase intent signals are the dominant conversion driver. Also strongly favored for marketplace-native brands without physical retail presence.
• Walmart Connect wins for: CPG, grocery, household consumables, OTC health, pet food, and brands with significant in-store velocity. Any category where the physical store is still the primary purchase channel benefits from Walmart’s omnichannel signal.
• Neither clearly wins for: Apparel, sporting goods, and furniture — categories where both platforms’ attribution is weakest and where Pinterest, Google, and Meta still deliver better top-funnel discovery economics.

What Do the Financial Trajectories Tell Us About Long-Term Platform Momentum?

The revenue scorecard matters for operators making multi-year investment decisions. Amazon’s advertising services segment generated $56.2 billion in 2025 full-year revenue, up 18% year-over-year, making it the company’s fastest-growing division and now larger than its AWS operating income contribution on an absolute basis. Amazon DSP is a meaningful slice of that total, though Amazon does not break out DSP revenue specifically.

Walmart Connect reported $4.4 billion in global advertising revenue for fiscal year 2026 (ended January 2026), up 27% year-over-year — outpacing Amazon’s ad growth rate for the third consecutive year from a smaller base. Walmart CEO Doug McMillon cited advertising as a key profitability driver on the Q4 FY2026 earnings call in February, and the company has committed to tripling Connect’s engineering headcount by end of 2026.

The trajectory gap is real. Walmart Connect is growing faster in percentage terms but remains at roughly 7–8% of Amazon’s advertising scale. For operators, that gap means Amazon still offers more inventory liquidity, better audience precision, and more mature tooling — but Walmart Connect’s acceleration means the competitive dynamic will look meaningfully different by 2028.

The bottom line: Amazon DSP remains the higher-ceiling platform for most ecommerce-native brands — its data depth, inventory liquidity, and tooling maturity are unmatched. But Walmart Connect has earned a seat at the planning table, especially for brands with real in-store velocity, CPG footprints, or budgets under $50K/month that previously couldn’t access programmatic retail media at this data quality level. The operators winning in 2026 are running both, using AMC for digital attribution depth and Walmart Luminate for omnichannel sales lift validation — treating them as complementary pipes rather than competing choices.