Retail Media: the third wave of digital advertising

After search (Google) and social (Meta), retail media has become the third great wave of digital advertising. According to GroupM/eMarketer estimates, it already represents over 20% of global digital media investment in 2026 and grows in double digits year-on-year — while the open web stagnates.

Why now

Retailers own the most valuable asset in the advertising ecosystem: real, deterministic and legally solid transaction data. On that foundation, they offer targeting and attribution no conventional walled garden can match. Amazon Ads was the pioneer; today Walmart Connect, Carrefour Links, Tesco Media & Insights and, in Portugal, Continente Media Group and the new El Corte Inglés Publicidade hub all operate at international level.

The on-site + off-site model

The mature offering is no longer limited to sponsored products on the retailer's own e-commerce (on-site). It extends to off-site campaigns — display, CTV, DOOH — activated with the retailer's audiences, measuring in-store purchase closure via loyalty ID. It is this on-to-offline link that sets retail media apart from any other media.

Implications for the Brand Manager

Retail media doesn't replace brand-building — it complements it. The MediaWorks recommendation is to combine upper-funnel campaigns on premium platforms (CTV, digital DOOH, YouTube) with retail media activation near the decision moment. Watch out for two common mistakes: (1) cannibalising traffic that would come organically, (2) fragmenting investment across dozens of networks without enough scale to measure.