Retail media networks are now meaningful share of the total ad pie. The reason is obvious: closed-loop sales data inside the platform. The problem, also obvious: that closed loop says nothing about what brought the buyer to the store in the first place.
The half-blind buy
When a marketplace platform reports 4x ROAS on its own ads, it's not lying — but it's also not telling you which of those buyers were already moving in your direction because of TV, OTT, search or social earlier in the week.
What cross-media adds
A single-source view links upper-funnel exposure to downstream marketplace and quick-commerce activity, so retail media can be evaluated alongside — not against — the rest of the plan.
Retail media is the receipt. Cross-media is the story that explains why it was written.