PayPal Ads positioned cross-merchant data as the proof point for retail media ROI at Cannes Lions 2026, with AdExchanger's on-site reporting framing the payment network's capabilities as a counterweight to retailer-bound measurement.

AdExchanger's Cannes 2026 dispatch, headlined "How PayPal Ads Proves Retail Media ROI With Cross-Merchant Data," captured the company's pitch to advertisers: retail media return can be tracked across the merchants in PayPal's checkout network rather than only inside one retailer's platform.

That framing matters for the category's structure. Retail media has largely grown up as a set of retailer-owned networks, each reporting on performance inside its own properties. A payment processor that sits at checkout across thousands of merchants stands apart from any single retailer, giving PayPal Ads a structural measurement claim the retailer-owned networks cannot replicate.

What this changes for ad buyers

For practitioners running always-on retail media budgets, cross-merchant data changes three planning workflows:

• Attribution no longer stops at the retailer boundary. Conversions tied to PayPal checkout can be matched against ad exposure across multiple merchants at once.
• Incrementality testing gains a third-party reference point, because PayPal's transaction record sits outside any single retailer's audience graph.
• Reporting consolidation becomes possible for advertisers running campaigns across several mid-market retailers that share PayPal at checkout.

What stays the same

Retailer-owned networks still control on-site placements and that inventory remains the bulk of retail media spend. PayPal Ads does not displace that. What it offers is a measurement layer that runs above single-merchant reporting.

Why Cannes Lions 2026

Cannes Lions has hosted the year's biggest retail media announcements across multiple cycles, including clean-room expansions and category updates from retailer-owned networks. AdExchanger's coverage slots PayPal Ads into that same conversation, with the explicit frame of cross-merchant ROI proof.

How does the integration work?

PayPal Ads draws on the company's existing commerce stack, which means advertisers already processing payments through PayPal can layer ad campaigns onto an active relationship. The differentiator from single-merchant networks sits in measurement, where PayPal anchors conversions to the actual settled transaction rather than to proxy engagement signals.

Open questions for adoption

Three questions will shape whether mid-market brands treat PayPal Ads as primary inventory or as a measurement overlay:

• How does cross-merchant reporting reconcile with the in-platform attribution each retailer-owned network already supplies?
• At what spend tier does PayPal Ads become economically viable versus a direct retailer deal?
• Does the cross-merchant view extend to non-PayPal transactions, or must the merchant opt in to PayPal checkout for the data to flow?

The bottom line

For now, the headline from AdExchanger's reporting is straightforward: the retail media ROI conversation at Cannes 2026 had a cross-merchant anchor, and PayPal Ads supplied it. Practitioners evaluating retail media budgets for the second half of 2026 now have a measurement alternative that runs above the retailer-owned networks rather than inside any one of them.