Glossy and Digiday both published comprehensive guides to retail media marketing this month, a simultaneous release that signals widespread marketer uncertainty about which networks deliver measurable return, according to content from both publications. The overlap suggests physical-product brands are spending into retail media without standardized frameworks to compare network performance.

Both guides address the same operational question: how to allocate budget across Amazon, Walmart, Target, Home Depot, and vertical-specific networks when each reports closed-loop attribution differently. Digiday's report frames retail media as a 2026 priority for marketers seeking verifiable sales lift; Glossy's version centers beauty and home-goods case studies, including The Home Depot and Milani Cosmetics, with contribution from agency Tinuiti. The simultaneous publication of similar frameworks from separate publishers indicates that no single network has established a dominant measurement standard.

The mechanism driving this confusion is architectural. Each retail media network owns its own point-of-sale data and defines conversion windows, attribution models, and incrementality tests independently. A beauty brand running identical campaigns on Amazon and Ulta receives incompatible reporting: Amazon attributes sales within 14 days of ad exposure; Ulta may use a 30-day window. Neither network shares raw basket data, so the brand cannot reconcile which platform drove the marginal sale. This creates a coordination problem where marketers default to the largest networks not because they deliver better ROI, but because budget committees understand them.

The solve for a smaller physical-product brand is to impose a single measurement layer across all networks before budget scales. Start with one product SKU and run it on three retail media platforms simultaneously for 60 days: Amazon Sponsored Products, Walmart Connect, and one vertical network relevant to your category. Set identical daily budgets—$50 per platform is sufficient—and identical target ACoS. Track sales in a shared spreadsheet, normalizing each network's attribution window to a consistent 7-day click standard by manually logging order timestamps from each dashboard.

At day 60, compare cost-per-acquired-customer across platforms using your own data, not the network's reported conversion rate. Calculate total ad spend divided by new-customer first orders, excluding repeat purchases the network may claim as conversions. This reveals which platform acquires customers at the lowest cost, independent of how each network wants to report success. Shift 80% of budget to the winner for the next 90 days, then retest.

The broader pattern is that retail media networks will not converge on shared standards because fragmentation benefits the largest players. Brands that wait for industry-wide measurement frameworks will spend years in confusion. The move is to build your own attribution spine now, while budgets are small enough to control, then carry that discipline forward as spend scales. The same trade publishers rushing guides to market are documenting the absence of consensus, not its arrival.