GumGum Appoints Marcus Startzel as Chief Executive Officer

GumGum, the contextual-first technology leader, announced that ad tech veteran Marcus Startzel has been appointed as its new Chief Executive Officer. The appointment marks a pivotal step in GumGum’s commitment to empowering its partners to achieve better advertising outcomes through the industry’s first Mindset Graph™.

As a former CEO, Startzel brings over two decades of experience in ad tech industry leadership, most notably with Millennial Media, AppNexus, Amazon, WBX Commerce, and AOL/Advertising.com. He began his career as a nuclear engineer and officer in the United States Navy after graduating from the U.S. Naval Academy with a degree in Mathematics. With the introduction of Marcus Startzel, GumGum strengthens this mission with a leader who shares a deep passion for solving customer challenges and driving real-world marketing results.

“In Marcus, we found somebody who is customer-obsessed and a natural leader with proven experience,” said Mark Suster, Managing Partner of Upfront Ventures and GumGum Board member. “I’m confident that under his leadership, GumGum will take our AI-powered Mindset Graph and platform to the next level and help lead the advertising industry through its inevitable changes.”



Artificial intelligence, through large language models (LLMs), machine learning, and Agentic AI, is transforming the media landscape that advertisers and publishers must navigate, with privacy changes and growing skepticism around quality and behavioral targeting. GumGum’s Mindset Graph is an AI-powered data engine that analyzes billions of signals across the open web—mapping consumer attention, contextual alignment, and creative performance in real-time to fuel smarter campaigns.

“Through every cycle of change, one thing is certain: great companies serve and deliver results for their customers,” said Startzel. “GumGum is redefining what it means to deliver advertising that aligns with consumer mindset and brand objectives—by leveraging AI to understand mindset and context. We will deliver wins for our customers through innovation, transparency, strategic investments in AI, and relentless focus on outcomes.”

The company’s solutions span display, video, CTV, and live sports through its Relo Metrics business, giving advertisers the tools to drive attention, engagement, and ROI—all while respecting consumer privacy. “GumGum isn’t just a contextual company. We’re a mindset company,” said Startzel. “And our job is to help our customers show up at the right moments, with the right message, in a way that drives growth. That’s the future of advertising, and it’s happening now.”

Also published in Martech360