Retail media is no longer a line item — it’s a budget category. By mid-2026, U.S. retail media ad spend has crossed $61 billion annually, according to eMarketer’s Q2 2026 Retail Media Forecast. Amazon still owns the lion’s share at roughly 75% of that figure, but Walmart Connect’s accelerating growth has created a genuine second-choice conversation among DTC brands, agency media buyers, and marketplace sellers who are finally willing to stress-test their Amazon dependency.
The question isn’t whether Amazon DSP is dominant. It is. The question is whether Walmart Connect has matured enough — in data quality, CPM efficiency, and off-site reach — to justify a meaningful budget allocation alongside Amazon. For operators running $5M to $50M in annual revenue, that budget decision is no longer theoretical.
How do Amazon DSP and Walmart Connect differ in scale and inventory access?
Amazon DSP gives advertisers programmatic access to Amazon’s owned-and-operated properties — Sponsored Display, streaming ads on Prime Video, Fire TV, Twitch, and an extensive network of third-party publisher sites through Amazon Publisher Services. Amazon’s addressable audience in the U.S. sits at approximately 167 million Prime members, and its identity graph is built on actual purchase behavior, not probabilistic modeling.
Walmart Connect, by contrast, reaches Walmart’s 139 million weekly U.S. shoppers across Walmart.com, the Walmart app, in-store digital screens, and off-site placements through its partnership with The Trade Desk — a deal that gives Walmart’s first-party data legs it didn’t have in 2024. Walmart’s on-site inventory skews heavily toward grocery, consumables, and everyday essentials, which matters enormously for CPG brands but creates a ceiling for niche DTC categories.
- Amazon DSP reach: 167M+ U.S. Prime members; 300M+ global active customer accounts
- Walmart Connect reach: 139M weekly U.S. shoppers; 4,700+ physical store locations adding in-store screen inventory
- Off-site inventory: Amazon Publisher Services network vs. The Trade Desk partnership for Walmart
- Video: Amazon leads decisively with Prime Video, Fire TV, and Twitch; Walmart has limited streaming inventory
- Minimum spend: Amazon DSP managed service typically requires $35,000/month; Walmart Connect self-serve starts at $1,000/month
Which platform delivers better ROAS and closed-loop attribution?
This is where the comparison gets genuinely competitive. Amazon’s closed-loop attribution — the ability to tie an ad impression directly to a purchase within Amazon’s walled garden — has always been its structural advantage. Amazon Marketing Cloud (AMC) allows sophisticated advertisers to run SQL queries across impression, click, and conversion data at the household level, giving enterprise brands attribution fidelity that no external DSP can match inside Amazon’s ecosystem.
But Walmart Connect’s attribution story has improved substantially since the 2025 rollout of its Walmart Luminate data platform, which connects ad exposure to both online and in-store purchase data across its 4,700 locations. For brands with significant brick-and-mortar exposure, that omnichannel signal is genuinely differentiated.
“We moved 18% of our Amazon DSP budget into Walmart Connect in Q1 2026 and ran a clean holdout test. Our blended ROAS on Walmart came in at 4.1x versus 3.8x on Amazon for the same SKU set — but only because we’re in a category where Walmart shoppers actually index higher. The lesson is that category fit matters more than platform reputation.” — Dana Cho, VP of Performance Marketing, Everspring Home (Target-distributed DTC brand)
Independent agency benchmarks from Tinuiti’s Q2 2026 Retail Media Report show Amazon DSP delivering a median ROAS of 4.6x across all categories, compared to Walmart Connect’s 3.4x median. However, Walmart’s CPMs are running 22% lower on average — meaning cost-efficient reach for budget-conscious operators is genuinely better on Walmart, even if the conversion rate is lower.
How does audience targeting compare between the two platforms?
Amazon’s data moat is its transaction history. With two decades of purchase data spanning hundreds of millions of SKUs, Amazon can build in-market audience segments with a specificity that Walmart cannot currently match outside of grocery and household categories. Amazon’s lifestyle segments, life event targeting, and lookalike modeling inside AMC are among the most granular available in programmatic advertising.
Walmart Connect’s targeting has matured through the Luminate rollout, offering purchase-based segments tied to Walmart’s first-party transaction data. Its partnership with The Trade Desk also enables Walmart’s data to be activated across the open web at scale — something Amazon’s walled garden approach deliberately limits. This is actually a meaningful edge for brands running upper-funnel prospecting campaigns that extend beyond retail properties.
“The Trade Desk integration changed the calculus for our off-site prospecting. We’re running Walmart’s purchase segments on premium publisher inventory and seeing CPAs that are competitive with Meta. That wasn’t possible two years ago.” — Marcus Webb, Head of Retail Media Strategy, Wpromote
- Amazon DSP targeting strengths: In-market purchase audiences, AMC custom modeling, Prime Video contextual, Alexa behavioral data
- Walmart Connect targeting strengths: Omnichannel purchase data (online + in-store), The Trade Desk open-web activation, Luminate demographic overlays
- Third-party data integration: Both platforms support select third-party data onboarding; Amazon’s is more restrictive
What are the real cost and access differences for mid-market operators?
Access asymmetry is one of the most operationally consequential differences between these two platforms. Amazon DSP’s managed-service minimum of roughly $35,000 per month has historically locked out brands under $10M in annual ad spend. Amazon’s self-serve Sponsored Display product fills some of that gap, but it lacks the full programmatic control of DSP proper.
Walmart Connect’s self-serve entry point — starting around $1,000 per month on its ad center — makes it meaningfully more accessible for emerging DTC brands and Walmart Marketplace sellers testing the channel. Walmart has also been more aggressive about onboarding agency partners, offering co-op deals and managed service tiers at lower minimums than Amazon.
For Shopify merchants selling across both Amazon and Walmart Marketplace, the operational math looks roughly like this: Amazon DSP is the right tool if you’re already doing $3M+ on Amazon and want to defend share and drive new-to-brand buyers; Walmart Connect is the right tool if you’re actively growing your Walmart.com assortment or have strong physical retail distribution that Luminate can track.
| Metric | Amazon DSP | Walmart Connect |
|---|---|---|
| U.S. Audience Reach | 167M+ Prime members | 139M weekly shoppers |
| 2026 U.S. Revenue (est.) | ~$46B (total retail media) | $4.2B run rate |
| Managed Service Minimum | ~$35,000/month | ~$5,000/month |
| Self-Serve Entry Point | Sponsored Display (limited DSP features) | $1,000/month (Ad Center) |
| Median ROAS (Q2 2026, Tinuiti) | 4.6x | 3.4x |
| Average CPM vs. Amazon | Baseline | ~22% lower |
| Closed-Loop Attribution | Yes (AMC, full purchase graph) | Yes (Luminate, incl. in-store) |
| Off-Site Programmatic | Yes (Amazon Publisher Services) | Yes (The Trade Desk integration) |
| Streaming/Video Inventory | Prime Video, Fire TV, Twitch | Limited; Vudu partnership |
| In-Store Ad Inventory | Whole Foods (limited) | 4,700+ store digital screens |
| Best-Fit Categories | All ecommerce; electronics, apparel, DTC | CPG, grocery, household, consumables |
| Agency Partner Program | Amazon Ads Partner Network | Walmart Connect Agency Hub |
Which platform is better positioned for Q4 2026 and beyond?
For Q4 2026, Amazon DSP retains a structural advantage rooted in consumer intent. Prime members searching and purchasing during Black Friday and Cyber Monday week generate real-time behavioral signals that Amazon can activate within the DSP in near-real-time — a capability no other retail media network can replicate at scale. Amazon’s recent rollout of Sponsored TV for mid-market brands, which dropped the Prime Video ad entry point to roughly $10,000 for the holiday window, is expanding access to video inventory that was previously enterprise-only.
Walmart Connect’s Q4 play is different but credible. Walmart’s physical store footprint becomes a genuine media asset during holiday — 4,700 locations with digital screens, self-checkout ad units, and in-store radio inventory that Amazon simply cannot match. For CPG brands and household brands running omnichannel campaigns, Walmart’s Q4 in-store reach is a meaningful complement to Amazon’s digital dominance.
“We’re allocating 70/30 Amazon to Walmart this Q4, but that Walmart 30% is doing real work for us in Midwest and Southeast markets where our Walmart.com velocity is actually stronger than Amazon. The in-store Luminate data gives us proof of incrementality that our CFO finally believes.” — Rachel Okafor, CMO, Fortify Wellness (DTC supplement brand, $28M annual revenue)
Looking at 2027 and beyond, the more interesting question is whether Walmart Connect can close the creative tooling gap. Amazon’s full-motion video creative builder, A/B testing infrastructure inside AMC, and new AI-powered creative optimization launched in May 2026 give Amazon DSP advertisers materially better creative infrastructure. Walmart’s creative tools remain comparatively basic, though the company has signaled a significant creative platform investment in its Q2 2026 earnings call.
Bottom line: Which platform should ecommerce operators prioritize?
This isn’t a binary choice, and any agency or brand treating it as one is leaving measurable revenue on the table. The practical answer depends on three operational variables: where your customers actually shop, what your category CPMs look like on each platform, and whether your margins can support Amazon DSP’s volume requirements.
- Choose Amazon DSP if: Your primary revenue channel is Amazon, your category has high purchase frequency on Prime, and you have the budget for managed service minimums. AMC’s query capability is unmatched for multi-touch attribution work.
- Choose Walmart Connect if: You sell in grocery, household, or CPG; you have Walmart Marketplace or physical retail distribution; or you’re seeking lower-CPM off-site prospecting through The Trade Desk pipeline.
- Run both if: You’re above $10M in annual revenue, selling across multiple channels, and want to build a retail media mix that isn’t entirely Amazon-dependent going into a potentially volatile 2027 tariff environment.
The smartest operators in 2026 are treating Amazon DSP as their high-intent conversion engine and Walmart Connect as their reach and efficiency layer — not competitors, but complements with different jobs to do. The brands still debating whether Walmart is “worth it” are increasingly the ones losing ground to competitors who already ran the test.
