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 [email protected] 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.
