Retail media is no longer a line item you test — it’s the operating infrastructure of modern ecommerce growth. Amazon’s Sponsored Products still dominate, but Walmart Connect, Instacart Ads, Kroger Precision Marketing, and a dozen emerging networks are forcing sellers to develop a coherent multi-network strategy or get outspent by competitors who have.
According to eMarketer’s Q1 2026 Retail Media Forecast, retail media ad spend in the U.S. will hit $67.4B by end of 2026 — up from $54.6B in 2024. Amazon still owns roughly 76% of that pool, but its share is compressing as Walmart Connect posts 38% year-over-year growth and Target’s Roundel quietly becomes a top-five destination for CPG and home goods brands.
The problem isn’t opportunity. The problem is fragmentation. Most brands running ads on two or more networks are doing it with disconnected tools, siloed data, and no unified attribution model. The result is wasted spend, cannibalized margin, and a lot of gut-feel budget decisions masquerading as strategy.
This guide walks through the exact steps to build a retail media strategy that compounds — across platforms, across categories, and across the full funnel.
What Is a Retail Media Network and Why Does It Matter Now?
A retail media network (RMN) is an advertising platform operated by a retailer that allows brands to serve ads against the retailer’s first-party shopper data — on-site, off-site, and increasingly in-store. Amazon Advertising is the dominant example, but the ecosystem now includes:
- Walmart Connect — 144M weekly shoppers, growing DSP and offsite capabilities
- Target Roundel — deep integration with Target Circle loyalty data, strong in CPG and apparel
- Instacart Ads — high purchase-intent grocery audiences, now expanding into non-grocery verticals
- Kroger Precision Marketing — household-level purchase data for CPG brands
- Chewy Ads — dominant in pet category, increasingly aggressive in sponsored placements
- Home Depot’s Orange Apron Media — launched full self-serve platform in late 2025
What makes RMNs structurally different from Google or Meta is closed-loop attribution. A brand can see whether an ad impression on Walmart.com resulted in a purchase — not a modeled estimate, an actual transaction. That’s why CFOs are paying attention.
How Do You Audit Your Current Retail Media Spend Before Adding New Networks?
Before you expand, you need to know what you actually have. Most sellers running Amazon Ads for more than 12 months have accumulated structural inefficiencies — orphaned campaigns, overlapping targeting, bids that haven’t been touched since 2024.
Step 1: Pull a full campaign audit across every active network. For Amazon, use Helium 10’s Adtomic or Perpetua’s campaign audit tool to extract ACOS, TACOS, impression share, and click-through rate by campaign type. Flag any sponsored product campaign with TACOS above 18% in a mature category — that’s a signal you’re buying incremental revenue at unsustainable cost.
Step 2: Identify your true incrementality. Amazon’s Brand Lift studies and Walmart Connect’s incrementality measurement tools both allow you to run controlled holdout tests. If you haven’t run an incrementality test in the last six months, your ROAS numbers are likely inflated by organic halo. Analytic Partners published research in March 2026 showing that 34% of retail media spend attributed to “incremental” sales was actually organic traffic that would have converted anyway.
Step 3: Map your category coverage. Build a simple spreadsheet: which categories are you selling in, which networks index highest for those categories, and where are your top competitors spending? Tools like Jungle Scout’s Competitor Intelligence, Stackline, or Profitero’s Share of Voice module can surface competitive ad presence data.
“Most brands come to us with three years of Amazon ad history and no idea what’s actually working. The audit always reveals the same thing — 60% of spend is running on autopilot and 20% of campaigns are actively cannibalizing each other.” — Sarah Lim, Head of Retail Media, Belardi Wong
How Do You Build a Full-Funnel Retail Media Architecture?
The mistake mid-market sellers make is treating retail media as purely a bottom-of-funnel harvesting tool. Sponsored Products are effective, but if you only bid on high-intent keywords, you’re ceding brand awareness to competitors who are running Sponsored Brands video, DSP display, and offsite retargeting against your own product pages.
Step 4: Build the funnel in layers.
- Top of funnel: Amazon DSP, Walmart Connect DSP, or Roundel’s programmatic display. Target category shoppers and competitor brand audiences 30-60 days before your peak selling window. Budget: 15-20% of total retail media spend.
- Mid-funnel: Sponsored Brands video, Amazon Streaming TV ads (especially effective for household and personal care categories), and Instacart’s Discovery placements. Budget: 20-25%.
- Bottom of funnel: Sponsored Products, Sponsored Display, Walmart Sponsored Search. This is where you close. Budget: 55-65%.
Step 5: Align your bid strategy to inventory position. This is where most sellers leave money on the table. If you’re running a Sponsored Products campaign and your FBA inventory drops below 30 days of cover, your bids should automatically step down — you don’t want to win traffic you can’t convert into stock. Perpetua and Pacvue both offer inventory-aware bidding rules. Set them up before Q4.
“The brands winning retail media in 2026 are the ones who’ve stopped treating it like paid search and started treating it like a media mix. That means full-funnel thinking, sequenced messaging, and creative that’s actually built for the format.” — Marcus Tran, VP of Commerce Media, Tinuiti
Which Retail Media Networks Should You Prioritize Beyond Amazon?
Step 6: Score networks against your category and margin profile. Not every network deserves budget. Use this framework:
- Category fit: Is your product category heavily shopped on this retailer’s platform? Home Depot’s Orange Apron Media is irrelevant to a supplements brand. Chewy Ads is irrelevant to apparel.
- Attribution maturity: Does the network offer closed-loop, SKU-level attribution? Some emerging RMNs still only report impressions and clicks. That’s not sufficient for budget justification.
- Minimum spend requirements: Walmart Connect’s DSP requires a $15K monthly minimum. Roundel’s managed service starts around $25K. If you’re under $5M in annual revenue, you may be better served maximizing Amazon and Instacart before expanding.
- Competitive whitespace: Emerging networks often have lower CPCs because category leaders haven’t fully committed. A home goods brand running Sponsored Ads on Wayfair’s Media Solutions in early 2025 reported CPCs 40-60% lower than equivalent Amazon placements.
For most sellers in the $2M-$20M GMV range, the priority stack looks like this: Amazon first, Walmart Connect second (if you’re listed there), Instacart third for consumables, and one emerging network as a test-and-learn channel.
How Do You Build a Unified Measurement Framework Across Networks?
Step 7: Choose a retail media measurement platform. Native dashboards are siloed and incomparable. To see true cross-network performance, you need a third-party aggregation layer. The leading options in mid-2026:
- Stackline — strongest for Amazon and Walmart, good Share of Voice reporting
- Skai (formerly Kenshoo) — enterprise-grade, supports 30+ retail media networks, strong for omnichannel CPG brands
- Pacvue Commerce — preferred by agency teams managing multiple advertiser accounts, robust automation rules
- Profitero — best for content and digital shelf analytics alongside ad performance
Step 8: Standardize your KPIs before you report to stakeholders. ROAS means different things on different networks. Amazon’s reported ROAS includes halo sales. Walmart Connect’s default attribution window is 14 days. Instacart uses a 7-day click window. If you’re comparing these raw numbers to each other, you’re comparing apples to avocados.
Define a single reporting standard: same attribution window (7-day click, 1-day view is reasonable), same incrementality methodology, and a unified TACOS metric that measures total ad spend as a percentage of total attributed revenue — not just campaign-attributed revenue.
“The moment you standardize your measurement across networks is the moment retail media stops feeling like a cost center and starts looking like a real growth lever. Until then, you’re just guessing.” — Jennifer Okafor, Director of Commerce Analytics, Omnicom Commerce Group
What Are the Biggest Operational Mistakes Sellers Make With Retail Media?
After auditing hundreds of retail media accounts, the patterns are consistent. Here’s what to avoid:
- Running ads without A+ Content or enhanced listing content in place. You’re paying for traffic to a product page that can’t convert. Fix the content before you scale spend.
- Ignoring dayparting on Walmart Connect. Walmart’s shopper behavior peaks differently than Amazon’s. Saturday morning and Sunday afternoon are high-conversion windows for grocery-adjacent categories. Default campaign schedules leave that performance on the table.
- Setting and forgetting negative keyword lists. Amazon’s broad and auto campaigns will serve against irrelevant queries indefinitely unless you’re actively harvesting search term reports and adding negatives weekly during ramp periods.
- Not aligning retail media spend with trade promotion calendars. If your brand is running a price promotion or coupon event, your retail media bids should increase during that window — conversion rate will be elevated and your ACOS will look better, making it the ideal time to buy impression share.
- Treating offsite retail media as display advertising. Amazon DSP offsite placements and Walmart Connect’s offsite product are retargeting retail audiences, not broad awareness plays. Creative needs to be product-specific and price/promo-led to perform.
Retail media is maturing fast. The networks that were experimental budget lines in 2023 are now core to how category leaders defend and grow share. The sellers who build disciplined, full-funnel, multi-network strategies in 2026 will have compounding data advantages — better audience models, better attribution baselines, and better relationships with retail media account teams — that will be very hard for slower movers to close.
Start with the audit. Fix the measurement. Then expand deliberately.
