Unlimitail: the Carrefour and Publicis retail media network, explained

Unlimitail is a shared network, not one retailer's media arm. Carrefour and Publicis own it, but its clients are some 40 retailers and the agencies that buy from them. Chief executive Alexis Marcombe says the company has its own offices and its own finance, IT and data systems, with confidentiality commitments that are contractual and auditable (The Media Leader FR, 9 November 2026). Marcombe says the company could not exist without that independence, since its clients include Carrefour's competitors.

Carrefour's weight is falling. Marcombe says Carrefour will be less than a third of Unlimitail's online activity by the end of 2026 and less than a quarter in 2027 (same source). In Germany Unlimitail works with Rewe and MediaMarkt; in Spain, with about fifteen retailers. For brands, the network is becoming a multi-retailer buy rather than a Carrefour buy. The company's 2021 forerunner for Carrefour alone is covered in the Carrefour Links profile.

The pitch is stores, not just websites. Marcombe argues that Amazon dominates online retail media in France but cannot follow retailers into physical stores in Europe. Unlimitail's answer is "omnichannel": measuring how ads change sales in shops as well as online. It runs A/B tests on outdoor screens near stores, measuring the sales effect by distance (same source). The retail media consolidation tracker follows how this alliance model is spreading.

Onsite. Retailers in the network sell sponsored products, banners and video. MaxiCoffee, for example, starts with Product Ads and Display Ads and can add Video Ads, Shoppable Ads and Brand Stores later (Unlimitail, 29 October 2026). Formats vary by retailer, so ask which apply to each site in your plan.

Offsite. Unlimitail sells retailer audiences on the open web, segmented TV, streaming and social platforms (Unlimitail, Solutions). Its "Social Retail" product, live in France from April 2026, connects Carrefour shopper data from 14 million card-holding households directly to social platforms, with Spain and Brazil to follow (Unlimitail, April 2026). Marcombe says the product is in beta with Meta and, in Europe, available only to Unlimitail's network. How retailer data travels offsite is explained in offsite retail media explained.

In-store and coupons. Unlimitail sells digital signage in stores, store windows and fuel stations, point-of-sale media and targeted paper and digital coupons (Unlimitail, Solutions). Its first media partners in 2023 included JCDecaux, M6, France Télévisions, Le Figaro and Brut (Publicis Groupe, 15 June 2023).

The data is each retailer's own transaction and loyalty data. Unlimitail says it processes data on 55 million Carrefour customers and 250 million customers in total (The Media Leader FR, 9 November 2026). Marcombe says Carrefour's data was structured from 2017 and has been used in clean rooms since 2019.

In June 2026 Unlimitail chose Snowflake Data Clean Rooms for a planned Global Retail Media Data Hub. The design keeps each retailer's data in its own environment while brands analyse shared audiences (Unlimitail, 18 June 2026). We found no launch notice for the hub by 9 November 2026.

Unlimitail measures on transactions rather than panels. Marcombe calls its measurement deterministic and its methods transparent, and he is sceptical of a single industry standard for every category (The Media Leader FR, 9 November 2026).

On 16 June 2026 NIQ and Unlimitail announced a measurement partnership. NIQ's tools become a core part of Unlimitail's stack, starting with Carrefour in France, Spain and Brazil, with pilots from mid-2026 (Unlimitail, 16 June 2026). The aim is to compare results across retailers and countries on one basis. We found no IAB Europe certification for Unlimitail.

1. Contact Unlimitail's sales teams for multi-retailer plans, custom data and measurement; the contact page is on unlimitail.com.
2. Use your DSP for Carrefour segments: more than 80 are self-service in The Trade Desk in France, with Spain and Brazil to follow (Unlimitail, 9 September 2026).
3. Use Pacvue or Skai for onsite sponsored products: Pacvue covers Carrefour France (Retail Technology Innovation Hub, 23 July 2025), and Skai covers Carrefour.fr and Plus.nl (Unlimitail, 23 April 2026).
4. Add YouTube through Google DV360, which Unlimitail has used for Carrefour audiences (The Media Leader FR, 29 February 2024), or Social Retail on Meta in France.
5. Agree the sales read with the team: which retailers and stores count, and whether NIQ or a clean room is used.

It suits:

• FMCG and specialist brands selling through several retailers in France, Spain, Germany or Brazil;
• agencies that want one contact for many retailers' media;
• brands that need in-store sales measured, not just online clicks.

It suits less:

• brands focused on one non-member retailer;
• buyers who need IAB Europe-certified metrics today;
• advertisers in markets outside Unlimitail's 21 countries.

• The shareholding split between Carrefour and Publicis.
• Unlimitail's revenue and the base for its 35% growth target.
• A full, current list of the 40 retailers.
• Page views: "more than 2 billion" (company boilerplate) versus "more than 3 billion" (June 2026 Snowflake release).
• The launch date of the Snowflake data hub and results of the NIQ pilots.

1. Publicis Groupe, "Carrefour Group and Publicis Groupe launch Unlimitail with its first 13 retail partners to seize the booming retail media market in Continental Europe, Brazil and Argentina" (15 June 2023). https://www.publicisgroupe.com/en/news/press-releases/carrefour-group-and-publicis-groupe-launch-unlimitail-with-its-first-13-retail-partners-to-seize-the-booming-retail-media-market-in-continental-europe-brazil-and-argentina
2. The Media Leader FR, "Alexis Marcombe (Unlimitail) : « Notre terrain, c'est le retail media omnicanal »" (9 November 2026). https://fr.themedialeader.com/alexis-marcombe-unlimitail-amazon-ne-viendra-pas-sur-le-terrain-du-magasin/
3. Unlimitail, "NIQ and Unlimitail Collaborate to Deliver the next Generation of omnichannel Retail Media Insights & Measurement across retailers and countries" (16 June 2026). https://www.unlimitail.com/news/niq-and-unlimitail-collaborate-to-deliver-the-next-generation-of-omnichannel-retail-media-insights-measurement-across-retailers-and-countries
4. Unlimitail, "Unlimitail Chooses Snowflake to Power Privacy-Preserving Retail Media Across Europe and Latin America" (18 June 2026). https://www.unlimitail.com/news/unlimitail-chooses-snowflake-to-power-privacy-preserving-retail-media-across-europe-and-latin-america
5. Unlimitail, "Unlimitail Partners with Skai to Open Carrefour and Plus.nl's High-Intent Commerce Audience to Global Advertisers" (23 April 2026). https://www.unlimitail.com/news/unlimitail-partners-with-skai-to-open-carrefour-and-plus-nls-high-intent-commerce-audience-to-global-advertisers
6. Unlimitail, "Unlimitail launches 'Social Retail' and shopper data takes over social media" (April 2026). https://www.unlimitail.com/news/unlimitail-launches-social-retail-and-shopper-data-takes-over-social-media
7. Unlimitail, "The Trade Desk and Unlimitail bring self-service access to Carrefour retail data across France, Spain and Brazil" (9 September 2026). https://www.unlimitail.com/news/the-trade-desk-and-unlimitail-bring-self-service-access-to-carrefour-retail-data-across-france-spain-and-brazil
8. Unlimitail, "Coopérative U chooses Unlimitail, France's leading omnichannel retail media player" (October 2026). https://www.unlimitail.com/news/cooperative-u-chooses-unlimitail-frances-leading-omnichannel-retail-media-player
9. Unlimitail, "MaxiCoffee, spécialiste de l'univers du café, accélère son activité Retail Media et rejoint Unlimitail" (29 October 2026). https://www.unlimitail.com/news/maxicoffee-specialiste-de-lunivers-du-cafe-accelere-son-activite-retail-media-et-rejoint-unlimitail
10. Unlimitail, "Our Solutions" and "For Retailers" (accessed 9 November 2026). https://www.unlimitail.com/solutions ; https://www.unlimitail.com/retailers