To meet the objectives of recruiting new buyers and enhancing customer value, the strategy implemented was based on three pillars:
- centralizing the management and expertise of cleanrooms under the same trusted third party (Numberly), in order to implement a system for processing 1st-party data identical for both retailers (Auchan and Intermarché);
- creating identical segments across the two retailers;
- a unified media activation and a robust incremental measurement.
First, Cassegrain and Numberly developed targeting based on the 1st-party data from both retailers. Five consumer segments were defined across the two retailers. Each segment was defined, for each of the two retailers, according to the same criteria, to ensure consistent activation across the entire initiative. Two filters specified the targeting: each segment consisted of individuals meeting two criteria, allowing on one hand, the recruitment of new buyers for the brand, and on the other hand, ensuring that the targeted individuals were indeed loyal to the retailer. The two criteria were the following:
- Criterion 1: Has not purchased the Cassegrain brand in over a year.
- Criterion 2: Has made at least 12 purchases at the store in the past year
After creating the segments on Liveramp, the campaign was delivered on the Open Web via the Xandr DSP using digital banners in 100% IAB formats, from March 10 to May 19, 2025, with an average weekly frequency of 3 impressions per individual. Segment performance was monitored throughout the campaign, and budget adjustments were made continuously based on the results.
A key aspect of the multi-retailer strategy was the integration of two types of measurement: attributed measurement and incremental test-and-control measurement. Both types of measurement were unified across the two retailers. This made it possible to evaluate and compare not only attributed performance but also the actual uplifts generated by the campaign.
