Mark Williamson and Sarah Marzano sit down for a candid conversation on the discipline required to build a retail media network that stays true to the “Costco Way.”
Key Takeaways
In this insightful fireside chat from the “What’s In Store for Retail Media Networks” event at NRF 2026, Mark Williamson (Costco) and Sarah Marzano (EMARKETER) move beyond the technical architecture to discuss the cultural and philosophical realities of retail media. For Costco, success isn’t measured simply by top-line ad revenue, but by how media serves the merchant and, ultimately, the member.
Williamson explores the power of saying “no” — specifically why Costco walked away from easy data monetization to protect the member experience. The discussion dives into the “translation” problem facing the industry: why media metrics like ROAS often fail to impress retail merchants who are focused on sales velocity, new buyer penetration, and category growth. From the extreme sensitivity of member feedback loops to the physical complexities of placing screens in a working warehouse environment, this session offers a rare, behind-the-scenes look at the friction between media ambition and retail reality.
Expect a grounded, expert discussion on why the “retail instinct” must always trump the “media instinct” and how retailers can embrace upper-funnel branding without losing sight of their core mission. For practitioners looking to bridge the gap between marketing agencies and merchant teams, this fireside chat provides the ultimate playbook for long-term alignment.
Speakers:
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Mark Williamson – Assistant Vice President, Retail Media, Costco
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Sarah Marzano – Principal Analyst for Commerce Media, EMARKETER