Brian Stempeck

The Story

The operator who keeps landing where attention is moving

Brian Stempeck was shopping for a pool heater. He did what a lot of people now do before a real purchase: he asked the machines. He typed the same question into ChatGPT, into Gemini, into Claude, and he read what came back. The answers did not agree. Different products, different reasoning, different confidence. For most shoppers that is a minor annoyance. For Stempeck it was a signal, and he had spent a career learning to trust those.

The moment lines up with a larger shift he had watched from the front row. "What I experienced - and what we all observed - is that these platforms are playing a larger role in shaping our research, behaviors, and decisions," he later said. If AI models were quietly becoming the place where people decide what to buy, then brands had a problem they could not see. They had no idea what the models were saying about them. Out of that gap came Evertune, the New York company Stempeck co-founded and now leads as chief executive.

To understand why he was the right person to notice it, you have to rewind about fifteen years, to a much smaller room.

Employee number eight

Stempeck joined The Trade Desk when it was barely a company - roughly the eighth person through the door. Over eleven years he took on business development, strategy, sales, client services and marketing, eventually holding the titles of Chief Client Officer and then the company's first Chief Strategy Officer. In 2019 he joined the board of directors. He founded and ran the New York office, which grew into the company's largest, and he helped push the business into Connected TV before that was an obvious bet.

The arc of that job is the part most founders would frame as the finish line. The Trade Desk went public and became one of the most valuable independent companies in advertising technology, worth tens of billions of dollars. Stempeck had equity, a board seat, and a comfortable perch. He could have stayed.

An unusual on-ramp

What makes his instinct for a shift like this less surprising is how many industries he had already passed through. He started as a political journalist at E&E Publishing, an outlet later folded into Politico. He moved into brand management at Unilever, working on Dove. He spent time at Bain & Company advising Fortune 500 clients on their online marketing and working in the private equity practice. He studied English Literature at the University of Virginia before earning an MBA at UNC's Kenan-Flagler Business School.

Journalist, consultant, brand manager, operator, founder. On paper it reads like five different people. In practice it is a résumé built for pattern recognition - someone who has watched enough industries reorganize themselves to notice when a new one is starting to.

Getting the band back together

Stempeck did not build Evertune alone. He called former Trade Desk colleagues Ed Chater and Poul Costinsky, who became co-founders as chief product officer and chief scientist respectively. It is a familiar pattern in company-building: a small group that already scaled something hard together, deciding to do it again. The trust is prebuilt, and so is the shorthand.

The product they built is a platform for what Stempeck calls Generative Engine Optimization. "Evertune is a comprehensive Generative Engine Optimization (GEO) and AI marketing platform that delivers complete AI search visibility," he says. In practice, Evertune measures how large language models - ChatGPT, Claude, Google's AI Overview, Gemini, Perplexity, Meta AI, DeepSeek - answer real buying questions, and whether a given brand shows up, gets recommended, or gets skipped.

The emphasis on scale is not an accident. It is the lesson The Trade Desk taught him: in a data business, volume is the moat. Evertune's pitch to a brand is that it can watch a million model responses a month and turn the noise into something a marketing team can actually act on. The company also offers custom surveys, because, as he puts it, "inevitably, every brand has its own use cases, and they want to test different things."

Naming a category before it has a name

One of the odder challenges of building Evertune is that the category itself is still forming. "LLMs are evolving constantly, and our category of GEO is so new that it doesn't even have one consistent name," Stempeck admits. Some call it GEO, some AEO for answer engine optimization, some just AI search visibility. When the vocabulary is that unsettled, an early company gets a rare privilege: it helps write the dictionary.

His framing for investors and customers is direct. He sees AI as the most significant new marketing channel since social media, and he is positioning Evertune for a world that goes well beyond monitoring. In his telling, AI agents will soon handle purchases, AI platforms will sell advertising, and commerce will happen inside AI ecosystems - and brands will need a way to optimize their mentions, buy media, and capture sales in all of it. Some of that is a bet on the future. But it is a bet informed by having watched programmatic advertising go from curiosity to infrastructure once already.

The early demand has been loud enough that Stempeck keeps flagging it as abnormal. In August 2025 Evertune announced a $15 million Series A led by Felicis Ventures, with returning backers Eniac Ventures, NextView Ventures and Roger Ehrenberg, plus angels from OpenAI, Meta and Uber. The cap table reads like a who's-who of his former world: Trade Desk alumni, adtech founders who have sold companies, and operators who have seen this kind of platform shift before.

The through-line

There is a tidy symmetry to it. Stempeck built The Trade Desk's New York office from nothing into its biggest, and he is building his second company from the same city. The instinct that carried him through journalism, consulting and adtech is the same one that made him pause over a disagreeing set of AI answers about a pool heater. Find where attention is moving, get there early, and build the tools to measure it before anyone else realizes they need them.

He also sits on the board of Nielsen, a company whose entire history is about measuring attention - which is either a coincidence or the most on-brand board seat imaginable. Either way, the work is the same as it has always been for him: figuring out where people are actually paying attention, and helping brands show up there.