By Ana Laura Zain for the Women in Retail Media Collective
While ad spend in retail media continues to climb toward the $100 billion mark, growth is no longer moving at breakneck speed. In this next phase, retail media networks (RMNs) are facing a reality check: What worked during the boom may not be enough to carry them forward.
Sarah Marzano, Principal Analyst, Retail and Commerce Media at EMARKETER, has a front-row seat to these shifts. EMARKETER’s latest research tracks where the market is headed and what strategies retail media leaders need to rethink.
In this Q&A, she shares her take on slowing growth rates, the fading appeal of the Amazon playbook, and why organizational alignment might be the most underrated part of retail media’s future.
1. Let’s start with your path into retail media. How did your career lead you to focus on this space and what drew you in?
I started my career in retail buying, first at Macy’s and later at Lord & Taylor, after graduating from FIT with a degree in merchandising. My path into market research and thought leadership came by way of a happy accident: a temporary cross-country move that took me far from where most retailers are based. With that transition, I discovered a different way to stay close to the retail industry, by leveraging data and analysis to help retailers, brands, and marketers make sense of the fast-moving landscape and make smarter decisions.
With a focus on retail and ecommerce, I first began covering retail media in the early days of the industry in my role as a retail analyst at L2, which was later acquired by Gartner. That early exposure to retail media planted the seed for what would become a deeper focus when I joined EMARKETER. In my current role I’ve had the opportunity to dedicate my research entirely to this space.
What continues to draw me in is the fast pace of the industry, as well as the convergence of commerce and media. Having started on retail merchant teams, I bring a perspective grounded in how retail actually operates, how decisions are made, how margins matter, and how media can move the needle. That foundation shapes how I approach my coverage of retail media today.
2. EMARKETER’s latest forecast shows U.S. retail media ad spending will surpass $100B by 2029, but with a slowing rate of growth. What’s driving this shift, and how should the industry interpret it?
We’re still seeing meaningful growth, but the year-over-year acceleration is slowing. That’s natural as the market matures. A major factor is Amazon’s decelerating pace—since it dominates the category, its slowdown affects the overall trajectory. But it’s not the full story.
We’re also seeing signs of diversification. Walmart and the fragmented cohort of “other” RMNs in our forecast are on track to grow faster than Amazon in 2025, which suggests a more distributed and competitive landscape. On-site formats still account for the bulk of spending, but they’re also the most mature, so their growth is tapering. The bright spots are in offsite and display advertising, which have more room to expand.
This isn’t a red flag, it’s a shift. Retailers and advertisers alike need to focus less on scaling at all costs, and more on optimizing strategy, differentiation, and value.
3. What can RMNs learn from Amazon’s success, and where should they chart their own path?
The limitations of copy-pasting Amazon’s model are becoming more clear. Amazon built incredible scale, particularly by activating long-tail advertisers, and that’s something other RMNs can learn from. Unlocking that mid- and lower-tier advertiser base is key for broader growth.
But most retailers won’t be able to replicate Amazon’s scale or depth of e-commerce behavior on their own. Relying solely on website traffic or sponsored products isn’t sustainable. Instead, RMNs should explore offsite media, loyalty integrations, better use of first-party data, and most importantly, strategies that align with their brand identity and category strengths.
The next phase of growth isn’t about replicating Amazon, it’s about understanding your unique value and designing a model that plays to it.
But building a distinct strategy isn’t just an external challenge, it also depends on strong internal alignment. And that often starts with one of the most overlooked relationships in retail media: the connection between media teams and merchants.
4. What are some of the most immediate steps leaders can take to break down silos between merchandising and retail media?
It starts with a mindset shift: retail media isn’t just a monetization tool, it’s a strategic growth lever. That means merchants need to be part of the planning conversation early, not brought in after the media plan is set.
Tactically, that could look like regular joint business planning between media and merchant teams, or even embedding media leads into merchandising orgs. Retailers should also align KPIs, if media teams and merchants are chasing different outcomes, collaboration will always be limited.
The best results happen when retail media is treated as an enabler of category success, not just an overlay on top of it.
But even with strong internal collaboration, another challenge remains: many advertisers have been buying media far longer than retailers have been selling it. That imbalance can shape how relationships are built, and where tensions emerge.
5. So how is that knowledge gap impacting relationships and outcomes, and how can RMNs close it?
It’s a real tension point. Many advertisers come in with deep media buying experience and high expectations around performance, attribution, and optimization. Retailers, by contrast, are still building that muscle. That knowledge gap can lead to misalignment, especially when it comes to proving value or managing campaigns in real time.
I see three key pillars to the solution. First, RMNs need to uplevel their media expertise, by hiring experienced talent, investing in training, and creating more robust operations. Second, they need to set expectations clearly and proactively. That means having open conversations with advertisers about what retail media can deliver, where it’s different from other channels, and how both sides can collaborate to drive results. Finally, retailers must work to address the friction advertisers experience in buying and reporting on retail media.
To truly compete in media, retailers should double down on what makes them distinct, deep shopper insight, proximity to purchase, and trusted consumer relationships.
6. Who are some of the women in retail media or marketing who inspire you and why?
I’m inspired by so many women in this space, but a few who truly stand out to me are Kiri Masters, Krysti Argylan, and Anne Hallock.
Kiri Masters has done an exceptional job of elevating the conversation around retail media. She brings both strategic clarity and operational depth, and she has a real gift for making complex industry shifts feel approachable and actionable. Her Retail Media Breakfast Club podcast has become a daily must-listen for me. It’s insightful, timely, and consistently sharp.
Krysti Argylan is a true pioneer in retail media. Her leadership at Target helped define what a modern retail media network could be. She set the bar in so many ways, and I’m genuinely excited to see how she shapes the next chapter at Uber Advertising.
And Anne Hallock, I met her on the conference circuit last year, and she’s been the embodiment of the idea that a rising tide lifts all boats. She’s incredibly passionate and knowledgeable about retail media, and also remarkably generous in sharing that knowledge and helping others make meaningful connections, especially among women in the industry.
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About us: The Women in Retail Media Collective (WRM Collective) is a network dedicated to empowering women in the retail media sector. By providing resources, thought leadership, and community, WRM Collective creates pathways for women to lead, innovate, and drive change in this booming sector. Founded by two industry leaders, WRM Collective is committed to fostering a more inclusive and equitable retail media landscape. For more information visit www.wrmcollective.com.