A highly lucrative new world is opening up for supermarket chains. This time, the “goods” are not on their shelves, in their fridges or in their warehouses. They are in the data of millions of consumers: their everyday purchases and the information they leave behind every time they pass through the checkout or place an online order.
This vast pool of information is becoming a new El Dorado for organised retail, creating a multi-billion-dollar market and giving chains the opportunity to boost profitability without having to increase product sales.
The new model, known as retail media, turns retailers — and supermarkets in particular — into advertising platforms, offering suppliers targeted exposure through apps, websites and physical stores. The “Grocery Retail Sector Outlook 2026” study by EY-Parthenon identifies it as one of the sector’s new growth drivers.
The figures are striking. According to WARC, global retail media ad spend is expected to exceed $202bn this year and reach $223.4bn in 2027. In Europe, the market is estimated at €16.9bn in 2025, with IAB Europe forecasting that it will reach €32.7bn by 2030.
Walmart alone generated $4.4bn in advertising revenue in 2024. Target brought in $649m from its advertising network, Roundel, while Carrefour is targeting revenue of €200m.
Greece is also part of this emerging market. EY-Parthenon sees significant scope for growth in retail media among Greek supermarket chains, which have a key advantage: access to consumers. With around 70 visits per customer a year, supermarkets can offer suppliers targeted advertising and the ability to measure its effectiveness.
How far can businesses go in the commercial use of personal data? In January 2026, France’s data protection authority, the CNIL, announced a €3.5m fine against a company that had transferred the contact details of loyalty-programme members to a social network for ad targeting without valid consent. In Greece, in August 2024, digital rights organisation noyb lodged a complaint against a supermarket chain after a customer requested access to the data linked to her loyalty card.
A separate issue is surveillance pricing — the possibility of prices varying according to data about a consumer’s profile. Unlike retail media, which concerns advertising revenue, the issue here is the price the customer is asked to pay.
On 28 October 2026, the US Federal Trade Commission (FTC) requested information from nine major companies, including Walmart, Target and Instacart, about their pricing practices. The investigation does not constitute a finding of illegal conduct.
A Consumer Reports study had previously found price differences of up to 23% for the same product among Instacart users. The company later announced that it had discontinued the technology in question.
In Britain, the Competition and Markets Authority (CMA) examined 50,000 products offered at special prices to loyalty card holders. The review, completed in November 2024, found no widespread misleading practices, although some offers proved more expensive than the lowest prices at rival chains.