Brands have spent the last three years hearing the same pitch: retail media networks let advertisers reach shoppers directly, without routing every dollar through Google or Meta. More than 200 retailers now run some version of a retail media network, from grocery chains to home improvement stores, according to industry trackers cited by Global Brands Magazine. The pitch worked. What advertisers got instead looks a lot like the thing they were trying to leave.
Of the roughly $10.5 billion in new US retail media dollars expected to land in 2026, about $9.42 billion, or 89 percent, is going to just two companies: Amazon Ads and Walmart Connect, according to eMarketer data reported by Business Insider and Digital Signage Pulse. That is not a slow drift toward concentration. It is most of the growth, captured by two retailers, while the other 200-plus networks split what is left. The eMarketer research also shows Amazon and Walmart’s combined share of total retail media spending was already above 84 percent in 2025, so 2026 is an acceleration of an existing pattern, not a new one.
Amazon’s own numbers explain why. The company’s advertising segment brought in $19.8 billion in the second quarter of 2026, up 26 percent year over year, with Amazon noting that inventory across Thursday Night Football, the NBA, WNBA, and NASCAR sold out, according to coverage of the earnings call by Exchange4Media and PPC Land. Walmart’s most recent fiscal filing told a similar story: Walmart Connect revenue rose 31 percent year over year, US retail media excluding Vizio rose 44 percent, and global advertising revenue overall jumped 50 percent, per Walmart’s own Q1 fiscal 2026 release as summarized by Global Brands Magazine. Two retailers with the shopper data, the checkout data, and the scale to sell both are absorbing nearly all the new budget.
Market size estimates vary depending on who is counting and what counts as retail media, which is itself worth noting before quoting any single number as settled fact. WARC puts the global retail media market near $200 billion in 2026. The IAB forecasts retail commerce media driving about $74 billion of US ad spend this year. The gap between those figures is not a contradiction so much as a reminder that retail media still has no settled definition: some trackers count only on-site search and display ads, others fold in off-site and in-store formats. What all of them agree on is the direction: more dollars, concentrating faster than the market itself is growing.
For a media buyer, the practical read is blunt. Testing a mid-tier retail media network still makes sense for incremental reach, but treating retail media broadly as a hedge against Amazon or Google dependency misreads where the budget is actually going. The diversification story and the concentration data are both true at once, and right now the concentration is winning.
Sources referenced in reporting:
- eMarketer data on Amazon and Walmart retail media concentration, via Business Insider / Digital Signage Pulse
- Amazon Q2 2026 advertising revenue coverage via Exchange4Media and PPC Land
- Walmart Connect and retail media market size figures via Global Brands Magazine
- IAB retail commerce media forecast