Retail media is forecast as Australia's fastest-growing ad channel, yet the two networks a local operator would actually buy, Coles 360 and Cartology, both posted their slowest growth ever in FY2026. The category is being carried by new inventory and new entrants, not by the incumbents' ads working harder. The lesson is to treat retail media as a maturing, single-digit-growth line, not a growth guarantee.
A line can be the fastest-growing one in the market and the slowest-growing one at the counter that sells it. Both are true in Australian supermarket advertising right now.
The Take: Retail media in Australia is not a growth story anymore. It is a maturity story, and the two networks you would actually buy have just told you so. Coles 360 and Cartology both posted their slowest revenue increase on record in FY26 while the market still calls the category its fastest-growing one. Read the seller charts, not the category chart, because the two now point different ways.
Why is Australia's biggest retail media growth slowing down?
Coles 360 grew its ad revenue 10% in FY26, down from 27% in FY23. That is a network maturing in plain sight, and the clearest signal you have about where this spend is heading.
The temptation is to read the category forecast and assume every dollar you put in rides that curve. It does not. The curve you fund is the seller's pace, and at the two biggest sellers that pace has fallen for four years straight.
The category chart and the seller charts disagree
The forecast reads like a boom. WPP Media has Australia's total ad market growing 7.4% to A$31.1 billion in 2026, with the category reaching A$2.3 billion and holding its title as the fastest-growing one, on track to pass total TV ad revenue by 2028.
Now read the two chains that sell most of that inventory. Coles 360's rate of increase has fallen every year it has reported it, and Cartology just recorded its slowest year.
Source: Mumbrella, reporting Coles 360 results across FY23 to FY26.
Woolworths sits in the same place. Cartology's rate fell to 7.8% in FY26, the lowest it has posted. Two chains, one direction, both sliding.
Cartology's FY26 result, the slowest year it has recorded
Where is the category growth actually coming from?
If the two biggest sellers are slowing and the category is still climbing, the increase is arriving from somewhere other than the incumbents' existing advertisers. It is. Coles 360 and Cartology together are nearing A$1 billion in annual ad revenue, and the expansion now comes from fresh sellers and new formats, from Wesfarmers and OneDigital to Amazon, Chemist Warehouse and Endeavour, plus in-store screens and offsite inventory the incumbents are still building out.
Sit with that for a moment. A category total pushed up by fresh entrants and new formats is a very different thing from a line where your dollars keep compounding. The market chart is measuring the arrival of new shelves. Your budget is buying a shelf that has been on sale for four years and is filling up.
What a maturing channel asks of your budget
Deceleration is not failure. It is what every ad format does once the early demand is spent and the first wave of advertisers has loaded in. Search did it. Social did it. Supermarket advertising is doing it now, roughly a decade behind the last one. The FY26 figures are the first clean reading of the bend.
The arc is familiar in any auction. Early buyers pile in, returns look strong because so few rivals are bidding, then the auction fills, prices rise and the pace bends back toward the wider economy. Google ran that arc. Meta ran it. Grocery advertising is on the same curve now, just younger.
That changes the job. A line rising at 27% forgives a loose plan, because the tide covers a lot. One rising at 10% does not. As the two chains mature, the best positions get more contested and the price of staying in front of the same shopper climbs. Treat this spend as a mature line item that competes for money, rather than a young one you feed on faith.
There is a concentration risk under all of it. Two retailers hold most of the shopper audience an Australian brand can reach this way, and a slowing duopoly defends its margin harder at renewal, not softer.
Every format graduates from land grab to maintenance. The businesses that win the mature phase are the ones that spotted the bend before the invoice did.
What I would actually do
Reset your expectation to the seller's pace, not the category forecast. If you are buying Coles 360 or Cartology, you are buying a line compounding in single digits, so plan and budget against that, not against the A$2.3 billion headline.
Use the slowdown as bargaining power. A chain rising at 10% needs your renewal more than one rising at 27% did. That is room to push on rate and on real access to the data behind their numbers.
Look hard at the fresh entrants before you assume they are the answer. Amazon, Chemist Warehouse, Endeavour and the OneDigital rollout are where the category is expanding, but the only reason to follow it is that your actual buyer shops there. Chase the audience, not the pace.
As the format matures, judge it on evidence rather than on the seller's dashboard. That is how we score a marketing function, and the full methodology sits at how we score a marketing function.
This is my read, not a forecast. Supermarket advertising in Australia will keep expanding, and for the right product in the right retailer it earns its place. My argument is narrower. The category chart is selling you a boom while the two chains you can actually buy are telling you the boom has matured, and the FY26 slowdown at Coles 360 and Cartology is the number that gives it away. If you want a mature-format plan built and read on evidence, that is the work we do inside NR Studio.
Frequently asked questions
Is retail media still worth buying in 2026?
For the right product inside the right retailer, yes. The change is that it is a maturing format now, so it should be planned and budgeted like a single-digit line rather than an infinite one.
Why are Coles 360 and Cartology slowing if the category is booming?
The category keeps climbing because fresh sellers and new inventory are expanding it. The two chains are maturing, so their year-on-year rates compress even as total category spend rises.
Where is Australian retail media growth coming from now?
From fresh entrants and new formats. Wesfarmers and OneDigital, Amazon, Chemist Warehouse and Endeavour are adding inventory, alongside in-store screens and offsite placements, so the incumbents are a smaller slice of the increase than the headline suggests.