Retail Media Consolidation: Amazon and Walmart Absorb 89% of 2026’s Ad Growth

Where 2026’s Retail Media Growth Is Actually Landing

U.S. retail media ad spending will climb from $60.32 billion in 2025 to $71.09 billion in 2026, a 17.8% year-over-year increase, according to eMarketer’s FAQ on retail media budget allocation. That looks like a healthy growth story until you ask who actually captures the roughly $10.8 billion in net-new spending. The same eMarketer analysis is blunt about it: Amazon and Walmart alone will absorb 89% of that incremental spend — an estimated $9.6 billion — leaving only about 11% for the other 100-plus retail media networks combined.

This is not a story about a rising tide. It is a story about two companies pulling away from a market they already dominate. Osmos’s 2026 retail media outlook puts Amazon Ads at 79.7% of the existing U.S. retail media market and Walmart Connect at 8.0% — a combined 87.7% of the base before the incremental skew is even counted. Amazon’s retail media revenue alone is forecast to exceed $75 billion by 2028, according to eMarketer’s H1 2026 retail media forecast — more than $65 billion ahead of the next-largest network, a gap so wide it no longer functions as competition in any conventional sense.

The concentration matters because retail media has become one of advertising’s biggest growth stories. Commerce media broadly — retail media plus adjacent categories like travel, hospitality, and financial services — reached $178.2 billion globally in 2025, surpassing television ad revenue for the first time, according to Marketing Brew’s 2026 commerce media outlook. A channel that size growing 89%-concentrated at the top changes the economics for everyone else building on top of it: agencies, ad-tech vendors, and the mid-market retailers who spent the last three years standing up their own ad networks on the assumption that scale would follow.

The M&A Wave Squeezing the Middle

As growth concentrates at the top, dealmaking is accelerating in the middle. Adweek’s 2026 commerce media preview notes that U.S. commerce media ad spend approached $59 billion in 2025 and that “dealmaking in commerce media is likely to heat up in 2026” precisely because growth is flattening for every network outside the top two. Four platform-level mergers have already landed this year: Spins acquired MikMak, Omnicom folded its TPN retail media unit into Flywheel, Podean bought Ad Advance, and Infillion acquired Catalina — a wave Adweek’s coverage of the M&A surge frames as a “land grab for data” among mid-tier players who can no longer justify running standalone ad programs.

Even companies with real scale are consolidating capability rather than competing head-on with Amazon. Walmart agreed on June 23, 2026 to acquire Vibe.co, a French connected-TV ad-tech firm, for $1.4 billion — its largest advertising investment in two years, according to Fortune’s coverage of the deal. The logic is defensive: Walmart Connect needs a self-serve, small-business-friendly CTV product to keep pace with Amazon’s ad stack rather than build one from scratch.

Delivery platforms are consolidating on the other side of the ledger — bundling scale across geographies instead of buying it. DoorDash’s own announcement describes folding DoorDash, Wolt, and Deliveroo into a single “Global Commerce Media Platform” serving more than 400,000 advertisers as of June 2026. Uber’s advertising business, meanwhile, crossed a $2 billion annualized run rate in late 2025 — more than double what it was a year earlier — proof that even non-retail platforms are racing to claim a slice of commerce media before the top of the market fully closes. Marketing Brew’s Freddy Dabaghi summarized the shift bluntly: “Consolidation is where we’ll start shifting more toward,” as marketers funnel spend through established ad-tech intermediaries like Criteo and Skai rather than manage dozens of separate retail media relationships.

What Brand Marketers, Network Operators, and Agencies Should Do

1. CPG and brand marketers: split budgets by measurement maturity, not by reach

Stop allocating retail media spend as a single undifferentiated line item. With Amazon and Walmart absorbing 89% of incremental dollars, the remaining budget going to mid-tier networks needs to be justified on measurement quality, not audience size. Demand closed-loop attribution and clean-room access before committing spend to any network outside the top two — a network that cannot show incremental sales lift is competing purely on price, and price competition is exactly what’s driving the current wave of shutdowns and mergers. Reallocate the marginal dollar toward whichever network can prove causality, even if its reach is smaller.

2. Mid-tier network operators: pick a defensible vertical before someone picks it for you

The “scaled second tier” that eMarketer describes is forming around specialization — grocery, home improvement, pharmacy — not around trying to out-scale Amazon. Networks without a clear vertical thesis by the end of 2026 are the likeliest acquisition or shutdown candidates, following the pattern already set by MikMak, TPN, Ad Advance, and Catalina. Operators should audit their own first-party data depth honestly: if it cannot support advertiser-facing incrementality measurement comparable to Walmart Connect’s, the network’s independent survival window is closing faster than most roadmaps assume.

3. Agencies: build cross-network measurement infrastructure now, not after the next merger

Every acquisition consolidates ad inventory but fragments reporting in the short term, as acquired platforms migrate onto new stacks on different timelines. Agencies managing multi-network retail media budgets should build (or buy) a measurement layer that normalizes performance data across Amazon, Walmart, and whichever mid-tier networks survive the current wave, rather than rebuilding dashboards after every deal closes. The agencies best positioned for 2027 are the ones that can already answer “what did the Catalina spend convert to under Infillion’s stack” without waiting for the acquirer’s own tooling to catch up.

The Concentration Risk Nobody’s Pricing In

The headline growth numbers in retail media — 17.8% year-over-year, commerce media overtaking television — obscure a market that is quietly becoming a duopoly with a long tail of acquisition targets attached. Osmos projects that five dominant ecosystems will control 80% of retail media spend by 2027, which means the current wave of mid-tier mergers is not a temporary correction — it is the market finding its permanent shape roughly two years ahead of most 2023-era forecasts.

For brands and agencies, the practical risk is not that retail media stops growing — it clearly is not — but that the option set keeps shrinking while measurement standards stay uneven. A marketer who built a five-network retail media program in 2024 may find, by the end of 2027, that two of those networks have been folded into acquirers with different reporting stacks and two others have shut down entirely. Planning retail media budgets on 12-month cycles, rather than locking in multi-year commitments to any single mid-tier network, is the more defensible posture until the consolidation wave settles.

Frequently Asked Questions

Sources & Further Reading

• FAQ on retail media networks: How marketers should allocate budgets in 2026 — eMarketer
• Retail Media Ad Spending Forecast H1 2026 — eMarketer
• 3 Ways Consolidation Will Hit Commerce Media in 2026 — Adweek
• A New Wave of M&A Shows That Retail Media’s Easy Growth Is Gone — Adweek
• Commerce Media in 2026: AI, Consolidation, and What Comes Next — Marketing Brew
• The Future of Retail Media: Retailers Becoming Media Networks — Osmos
• Walmart’s $1.4 Billion Vibe.co Deal Is a Direct Shot at Amazon’s Booming Ad Business — Fortune
• DoorDash Ads Becomes a Global Commerce Media Platform — DoorDash