WHSmith just launched a retail media network (RMN) to bring retail media to its airport stores. Like every other RMN launched since Amazon, Walmart, and Best Buy pioneered retail media over a decade ago, WHSmith promises “more exciting and engaging retail experiences for consumers” and is “tailored to the needs of … supplier brands.”

Our take: WHSmith’s network is yet another addition to the long tail of Amazon Ads copycats — and Amazon Ads’ scale leads other RMNs to project unrealistic growth. In the US, Amazon Ads is larger than all other RMNs combined. It’s growing faster than others and now selling advertising technology as a service, signaling sustained dominance.

For smaller RMNs, operational realities interfere with execution. Advertisers tell us that they lack media know-how, mask trade promotion as media spend, and struggle to prove performance. Here are the facts:

  • When retail media grows, trade funding declines. More than half of retail media ad spend comes from existing trade and shopper marketing budgets. Rather than earning incremental revenue, RMNs divert dollars that would have funded temporary price reductions, featured endcaps, and in-store demos into advertising. Retailers obscure RMNs’ inability to tap into digital and national media budgets by consolidating trade and retail media when reporting revenue publicly. Cannibalizing co-op funds remains a chief concern of executives at large RMNs, especially for multicategory, multibrand retailers.
  • RMN execution is weaker than it should be. RMNs struggle to demonstrate incrementality, power real-time results, and offer self-service platforms, making it difficult for brands and agencies to plan, buy, and optimize ads. In fact, most RMNs remain mostly manual. Furthermore, despite in-store ads earning more attention than any other format, according to Forrester’s Consumer Benchmark Survey, 2024, in-store ads remain constrained by their difficulty to buy and measure. The few retailers that have invested in smart carts and digital displays have yet to roll them out nationally due to the capital expenditure that they require and their uncertain return on ad spend.

Going forward, RMNs should prioritize self-service. Retail media is run by several ex-agency staff hired by RMNs to manage campaigns. Each RMN has tons of advertisers, so when media management is manual, it creates a lot of low-level labor that could be better spent on capabilities such as analytics. Resource-intensive, white-glove service may satisfy retailers’ largest first-party sellers, but there’s a long tail of first- and third-party sellers interested in allocating performance media budgets to self-serve highly relevant, revenue-generating ads. When they’re more self-service, RMNs have bigger budgets for sales, marketing, product, and engineering to focus on maximizing onsite profitability, full-funnel measurement, and making retail media programmatic.

To learn what else RMNs should prioritize, check out The State Of Retail Media, 2025, by Sucharita Kodali and myself. We clarify retail media’s potential and challenges and advise how retailers can sell more ads. As always, feel free to schedule time to discuss.