Brian O'Kelley

Brian O'Kelley is widely regarded as one of the founding fathers of programmatic advertising, having invented the first ad exchange while serving as CTO at Right Media — a breakthrough that fundamentally restructured how digital advertising inventory is bought and sold. That innovation led to Yahoo!'s acquisition of Right Media for approximately $850 million in 2007, validating the transformative potential of automated, auction-based ad trading. His technical vision and entrepreneurial instincts established him as one of the most consequential architects of modern AdTech infrastructure. In 2007, O'Kelley co-founded AppNexus, which grew under his leadership into one of the largest independent programmatic advertising platforms in the world, serving publishers, advertisers, agencies, and ad networks globally. He guided the company through more than $350 million in venture capital funding before AT&T acquired AppNexus in 2018 for $1.6 billion, integrating it into what became Xandr. His tenure at AppNexus cemented his reputation not only as a builder of scalable technology but as a fierce advocate for an open, transparent, and competitive programmatic ecosystem. After departing AT&T/AppNexus, O'Kelley co-founded Scope3 in 2020, pivoting his focus to one of the industry's most pressing emerging challenges: the carbon footprint of digital advertising. Scope3 provides emissions measurement and supply chain decarbonization tools, helping brands, agencies, and platforms understand and reduce the environmental impact of their media spend. This evolution reflects O'Kelley's pattern of identifying structural inefficiencies in AdTech and building infrastructure-level solutions to address them — this time at the intersection of advertising and climate accountability.

• B.S., Computer Science, Dartmouth College

• Invented the first ad exchange at Right Media, leading to a ~$850M acquisition by Yahoo! in 2007
• Co-founded and led AppNexus to a $1.6 billion acquisition by AT&T in 2018
• Raised over $350 million in venture capital for AppNexus
• Co-founded Scope3 in 2020 to bring carbon accountability to the digital advertising supply chain
• Widely credited with laying the technical and commercial foundation for the modern programmatic advertising ecosystem

• Frequent contributor and interview subject in AdExchanger, Digiday, and The Trade Desk industry forums