How Debenhams quadrupled Retail Media revenue with Mirakl Ads

As the Debenhams marketplace has scaled, Retail Media has been a revenue stream which needed an overhaul, not just due to the demand from their 15,000 plus sellers, but also to improve conversion rates which signal a better experience for shoppers. That’s why they opted to leverage Mirakl Ads and the results have been outstanding.

It’s worth nothing that with their 15k sellers and over 6 million products, marketplace revenue on Debenhams exceeds their first party sales and this is where the real wins for Retail Media come.

The challenge Debenhams wanted: Relevance at scale: As assortment expanded, Debenhams needed more consistent matching of ads to shopper intent to protect the customer experience and improve performance. Faster iteration: The team wanted a quicker cadence of optimisation and feature evolution to keep up with a fast-moving retail media landscape.

Stronger performance upside: With ambitious growth targets, Debenhams needed more headroom to lift conversion and unlock incremental revenue from sponsored products. More hands-on enablement: They also looked for deeper support to help accelerate campaign optimisation, seller education, and day-to-day execution.

The solution Mirakl Ads was selected for its ability to deliver: Proven algorithmic quality: Mirakl Ads’ AI-powered engine uses hybrid search (syntactic and vector) and multi-armed bandit (MAB) technology to ensure the most relevant products win every auction, significantly improving CTR and conversion.

Marketplace integration: Designed specifically for marketplaces, Mirakl Ads offers a seamless self-service experience for 3P sellers, who can manage ads directly within their existing Mirakl back-office. Agility and speed: Mirakl’s ability to execute a complex migration — involving 1,300 campaigns and 6M products — in just three weeks was a decisive factor.

Expert support: Debenhams valued the consulting-led approach and hands-on support provided by Mirakl to ensure the program’s long-term success. The results Within just two months of switching from their previous provider to Mirakl Ads, Debenhams saw step-change improvements across every key performance metric.

4× revenue uplift: The “MVP” revenue baseline increased fourfold versus the previous solution. Stronger investment momentum: Advertiser investment increased significantly, with daily spend up ~350% over the period—reflecting growing seller confidence and the platform’s ability to scale efficiently.

Significant conversion lift: Conversion rate (CVR) rose by +145%, demonstrating more relevant ad matching and better shopper experience. Broader advertiser participation: Active advertisers increased by +62% in the first few weeks, accelerating adoption quickly after launch.

Exceptional efficiency: ROAS more than doubled by +148%, showing that higher scale came with stronger performance — not trade-offs. The success of Mirakl Ads on Debenhams. com has already paved the way for expansion. The program has already scaled to include boohoo.

com, and future phases include the introduction of upper-funnel ad formats and the launch of retail media across additional websites within the Group. Looking to turbocharge your sales with Mirakl Ads on Debenhams? Reach out to debenhams-miraklads@mirakl. com to get started!

Once you’ve done that, the team at Debenhams will be running a webinar on Wednesday 13th May at 11am where they’ll give you all of the tools you need to get started and scale your campaigns…. So look out for a return email with instructions on how to sign up in the coming days.