The basic idea is simple and effective: why not advertise where people are already in a shopping mood? Retail media offers exactly that: the opportunity to reach consumers directly at the point of purchase, on the retailers' platforms. What was a niche marketing concept a few years ago has now grown into a multi-billion dollar advertising format: according to eMarketer, global advertising spending on retail media grew from nearly $67 billion in 2020 to $140 billion in 2024. This accounts for roughly one-fifth of global digital advertising spending. In Germany, $2.73 billion was spent on retail media last year.

The appeal lies in the fact that advertisers can use retailers' first-party data to display personalized ads during the shopping process. This is not only effective but also advantageous from a data protection perspective, as it eliminates the need for third-party data. Retail Media Networks (RMNs) have professionalized this idea, while the market is becoming increasingly fragmented due to many new providers.

Retail Media is Shaking Up the Advertising Ecosystem

A notable change that comes with the rapid expansion of RMNs is that retailers are becoming complex media companies, using their digital reach and first-party data to offer targeted advertising opportunities and formats. E-commerce platforms are expanding their advertising infrastructure. As a result, advertising budgets are increasingly shifting from general environments to data-driven, context-dependent retail media channels.

The problem is that with the growing fragmentation of the advertising ecosystem, the transparency and measurability of advertising effectiveness are taking a back seat because many RMNs have developed their own metrics and reporting methods. RMNs operate almost as advertising agencies: they manage brands' campaigns and are responsible for implementing third-party measurements and optimizations. However, the industry is evolving: more and more larger RMNs are now offering self-service platforms that allow advertisers to set up and manage their campaigns directly.

Without unified measurement procedures, it is almost impossible for advertisers to compare performance across different platforms or to optimize budgets in a data-driven way. This is why uniform, cross-channel standards are essential for the traceable allocation of advertising budgets spent on retail media.

Transparency Remains the Biggest Challenge

The situation is further complicated by the fact that advertisers pay a premium price for access to valuable consumer data. This puts pressure on both RMNs and brands. Both parties must justify the high investments, even in the absence of clear measurability and comparable metrics—at a time when every advertising euro spent must produce measurable results. Transparency therefore remains a central challenge and is fundamental to building trust between brands, retailers, and consumers.

Retail Media and Off-site Inventory? Absolutely!

Transparency is needed not only for on-site inventory, such as a retailer's own platforms, but also for off-site inventory. With off-site advertising, advertisers can extend their ads to surfaces beyond the retailer's platforms. Meanwhile, RMNs use the same first-party consumer data, leveraging the benefits of retail media at additional touchpoints. However, analyses show significant performance differences: user engagement on on-site surfaces is significantly higher than for off-site placements.

To-Dos for Successful Retail Media Campaigns

Demand data-driven transparency! Advertisers must insist on uniform reporting for impressions, clicks, conversions, and sales—regardless of whether the ad runs on a retailer's website or a third-party channel. This requires comprehensive data collection and analysis across all channels, providing differentiated insights into performance indicators.

Strategically leverage the proximity to the shopping process! In retail media, transparency isn't just about knowing where the ad ran. It's about being able to measure the direct impact of campaigns on conversions and sales. This allows advertisers to best leverage the benefits of being close to the shopping process.

Participate in the development of cross-channel performance measurement standards! There are currently no clear standards on how to calculate retail media metrics. Some RMNs use their own, unique methods to define metrics. In contrast, industry players could make the return on advertising budgets more traceable with unified, transparent standards, and thus fully exploit the potential of their investments. To this end, the active cooperation of advertisers, RMNs, and the entire marketing industry is key to developing best practices. Such partnerships would allow all stakeholders to introduce unified transparency and performance measurement tools to the world of retail media.

Ensure brand protection! (Brand Suitability) When selecting RMNs, it is important to pay attention to brand suitability tools, as the risks differ significantly between on-site and off-site placements. On-site placements on retailer websites show a much lower risk rate compared to off-site placements. A thoughtful brand suitability strategy with the right RMN partners not only protects the brand but also maximizes campaign impact through relevant placements and positive brand association.

Summary

For advertisers, transparency is the most important factor for trust, effectiveness, and long-term advertising success achievable with retail media. A comprehensive evaluation requires cross-channel measurement that provides detailed insight into performance across the entire advertising inventory. To this end, the industry needs a common standard that allows advertisers to compare and optimize their spending across platforms. Those who already rely on trustworthy RMNs that meet these transparency requirements today will achieve better results tomorrow.