Retail Media Beyond Amazon and Walmart: A 2026 Playbook for Instacart, Roundel, and Kroger Precision Marketing

US brands will spend roughly $71 billion on retail media in 2026. That number gets quoted in every board deck. The part that doesn't get quoted: Amazon and Walmart will capture more than 89% of the incremental growth, about $9.4 billion of the $10.5 billion in net-new spend. Amazon Ads alone holds 79.7% of the market. Walmart Connect takes another 8%. Every other retail media network on earth is fighting over the remaining 12.3%.

So why would a brand doing $5M to $100M in ecommerce revenue bother opening a second-wave network? Because that remaining slice is where you find buyers the top two can't reach. A grocery shopper filling an Instacart cart. A Target guest who never opens the Amazon app. A Kroger household with a decade of purchase history behind it. The question was never whether these networks matter. It's which one earns a place in your budget next, and in what order.

We've watched brands across our portfolio turn these networks on. Some found real incremental revenue. Others lit money on fire chasing a logo. The difference came down to a handful of decisions made before the first dollar of spend. This is how we think about them.

The Retail Media Market in 2026: Where the Other 11% Lives

Retail media is now roughly 30% of all US digital ad spend. The category grew about 18% year over year. But that growth is lopsided. The average brand already works with six retail media networks and expects to run eleven by the end of 2026, according to a Skai and Stratably survey of 166 advertisers. Fragmentation is the story now, not adoption.

The networks pulling advertiser dollars fall into a few buckets. Grocery delivery, led by Instacart. Mass retail, led by Target's Roundel. Grocery loyalty, led by Kroger Precision Marketing. Drugstore and health, through CVS Media Exchange and Walgreens Advertising Group. And a long tail of vertical specialists: The Home Depot's Orange Apron, Lowe's Media Network, Best Buy Ads, Chewy, and Albertsons Media Collective, plus Wayfair, Ulta, and DoorDash.

You will not run all of them. You shouldn't. The operators who win here are ruthless about sequencing, because every network you add carries a real cost that has nothing to do with media spend. More on that later.

The Second-Wave Networks Worth Knowing

Here's the shorthand we use internally when a client asks which network to consider next. Treat the minimum spend figures as directional; they include enough ad budget to actually read a signal, not the platform floor.

Network	Shopper base	Realistic monthly entry	Best-fit categories	Attribution model
Instacart Ads	Grocery delivery across 1,500+ retail banners	$15K to $40K	CPG, food and beverage, better-for-you, household	Closed-loop on-platform, adding in-store via Caper Cart
Roundel (Target)	Target guests, heavy in beauty, home, apparel	$20K to $50K	Beauty, home, baby, seasonal, apparel	First-party guest data, second-price auction on search
Kroger Precision Marketing	65M+ households, 2,800+ stores	$20K to $50K	Grocery CPG, health, beauty, pet	Loyalty-card closed loop, 3,500+ data signals
CVS Media Exchange	70M ExtraCare members	$15K+	Health, wellness, beauty, pharmacy-adjacent	Closed-loop via ExtraCare purchases
Chewy	~20M monthly users, pet-exclusive	$15K to $30K	Pet food, supplies, health	On-platform purchase attribution

Instacart Ads: The Grocery Channel That Beats Amazon's ROAS

If you sell anything that ships in a carton, Instacart deserves a hard look. Its reported grocery ROAS sits around $5.25, ahead of Amazon's roughly $4.92 for equivalent grocery categories. Sponsored Products benchmark in the 4.8x to 6.7x range for 2026. The engagement gap is even more striking: Instacart click-through runs 5.2% to 8.1% against Amazon's roughly 0.59%, and conversion lands between 18% and 25% versus Amazon's 11.5%.

Why so high? Intent. Someone building an Instacart order is mid-purchase, not browsing. Sponsored Products is the workhorse. Shoppable Display and Shoppable Video handle discovery on a CPM basis. In 2026, Instacart also pushed into in-store through Caper Cart activations and added multi-touch attribution that spans digital and physical baskets. For a CPG-adjacent brand, this is often the highest-efficiency channel outside Amazon. It doesn't replace Amazon. It reaches the trip Amazon doesn't own.

Roundel: Target's Quiet Compounder

Roundel posted $246M in ad revenue in a single quarter of fiscal 2026, up from $163M a year earlier, and Target expects the business to double in value over five years. It's now running a second-price auction on Target Product Ads and rolling out AI-driven audience tools that, by Roundel's own reporting, drove sharp CPM reductions and large click-through gains. Roundel even became the first retail media network to buy into DirecTV's out-of-home inventory.

The fit is category-specific. If your brand lives in beauty, home, baby, or seasonal, Target's guest base skews toward you in a way Amazon's does not. If you sell industrial supplies or niche electronics, Roundel is the wrong door. Match the shopper, not the headline growth rate.

Kroger Precision Marketing: The Data Play

KPM, powered by 84.51°, is the network we point data-serious grocery brands toward first. It sits on more than 65 million households of first-party purchase data, 2,800-plus stores, and 3,500-plus signals for building custom audiences. The Path to Purchase Institute ranked it number one for targeting effectiveness and measurement capabilities. KPM reports its ads lifted average sales 5.1x per thousand households against third-party alternatives, and a consolidated 84.51° Stratum dashboard arrived in early 2026 to pull reporting together.

The catch is the same as every retailer-reported number: KPM grades its own homework. The data quality is genuinely strong. The measurement claims still need an independent check, which brings us to the part most brands get wrong.

The Drugstore and Vertical Networks

CVS Media Exchange (about $250M in annual revenue, 70M ExtraCare members) and Walgreens Advertising Group (about $180M, 100M-plus loyalty members) matter almost entirely for health, wellness, and beauty brands with closed-loop attribution needs. Chewy owns pet. Best Buy Ads owns consumer electronics through its Criteo and Google partnerships. Lowe's and The Home Depot own home improvement. These are precision instruments. Open one only when your category and the retailer's shopper base line up almost perfectly.

How We Decide Which Retail Media Network to Open Next

The real question isn't which network to add. It's which network's shopper base will drive an incremental sale at a fee stack you can absorb. Across our client portfolio, we run every candidate through five filters before recommending spend.

1. Shopper-base overlap. Does this retailer's buyer actually match your customer? A supplement brand belongs on Kroger and CVS. It has no business on Best Buy Ads. This filter kills more networks than any other.
2. First-party data quality. Loyalty depth decides targeting precision. Kroger's 65M households and CVS's 70M ExtraCare members are worth more than a network with reach but thin identity.
3. Minimum spend versus P&L headroom. Once you add platform floors, tech-stack fees, and team hours, the true entry ticket on most second-wave networks lands between $15K and $50K a month. If that spend can't clear your contribution margin at a realistic ROAS, the network isn't ready for you yet.
4. How the network attributes. View-through generosity, look-back windows, and in-store credit vary wildly. A 30-day view-through window will always look better than a 7-day click window. Know which one you're being sold.
5. Whether independent lift is feasible. Can you run a real holdout or geo test on this network? If not, you're accepting the retailer's word on incrementality, and that word is always flattering.

This sequencing framework is the core of how we manage multi-channel ecommerce accounts. It's also why we rarely tell a brand to open three networks at once. You add one, prove it, then add the next.

The Measurement Problem Nobody Wants to Talk About

Every retail media network reports its own ROAS on its own auction. That's like asking a salesman whether his product is worth the price. It's the whole reason 75% of advertisers name incrementality as their single biggest measurement challenge, and only 15% feel very or extremely effective at measuring what their retail media spend actually contributes.

The 2026 shift is away from self-reported ROAS toward independent methods: test-versus-control holdouts, geo lift studies, and media mix triangulation. We've found the discipline that matters most is refusing to let a network's dashboard be the final word. When we turn on Roundel or Instacart for a client, we build a measurement plan first, then spend. If we can't isolate incremental lift within a quarter, we say so plainly and redirect the budget somewhere we can.

Incrementality also can't be read from media data alone. You need visibility into the surrounding commerce conditions: price, promotion, organic and paid rank, ratings, buy-box status, and retail distribution. A campaign that looks like a hero on the network dashboard may just be catching sales a price cut already created. This is the same measurement rigor we bring to Amazon strategy, applied one layer up, across networks.

The Operational Tax of Running Six Networks

Here's the part the vendor decks skip. Every network you add is a separate login, a separate auction, a separate creative spec, a separate billing cycle, and a separate report that never reconciles with the others. The average brand running six networks today, heading toward eleven, is drowning its ops team in browser tabs.

The commerce media tooling exists to help. Pacvue powers more than $12 billion in ad spend across 100-plus networks. Skai and Perpetua serve different tiers of the same problem. In April 2026, The Trade Desk, Pacvue, and Skai launched a unified integration spanning 250-plus commerce media partners, so programmatic and retail media can be activated and measured together. Tooling closes part of the gap. It doesn't close the strategy gap, which is deciding what to run and how hard.

Be honest with yourself about capacity. A single strategist can run Amazon and one or two secondary networks well. Six networks run part-time by a stretched team is how you end up with three of them quietly wasting spend while nobody notices. That's the real argument for consolidating retail media under one operator: not the tabs, the accountability. Someone has to own whether the whole portfolio is incremental, not just whether each dashboard looks green.

Where to Start

If you're only on Amazon, get Amazon right before you open anything else. If Amazon is stable and you sell grocery-adjacent CPG, Instacart is almost always the highest-value next move. If you live in beauty or home, look at Roundel. If your edge is data and you're in grocery, Kroger. One network, proven with real incrementality testing, beats five networks bleeding spend in the dark. If you want a straight answer on which one fits your P&L and your buyer, tell us what you sell and where, and we'll tell you where we'd spend next.