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Brian O'Kelley

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Brian O'Kelley is Co-Founder and CEO of Scope3, where he is focused on decarbonizing digital advertising. He previously co-founded and led AppNexus as CEO from 2007 to 2018, and before that served as CTO of Right Media, where he invented the first ad exchange — an innovation that helped give rise to programmatic advertising and led to Right Media's acquisition by Yahoo!.

Last updated Jun 6, 2026 by the ATDb Editorial Team

Role
Co-Founder and CEO
Company
Scope3
Based
New York, New York, United States
Boards
1
Connections
1
Years in industry
22 years

Bio

Brian O'Kelley is Co-Founder and CEO of Scope3, where he is focused on decarbonizing digital advertising. He previously co-founded and led AppNexus as CEO from 2007 to 2018, and before that served as CTO of Right Media, where he invented the first ad exchange — an innovation that helped give rise to programmatic advertising and led to Right Media's acquisition by Yahoo!.

Career

  • CEO and Co-Founder

    AppNexus · 2007-2018

  • CTO

    Right Media · 2003-2007

  • EVP, Technology

    Yahoo! (post Right Media acquisition) · 2007-2007

Board memberships

Scope3 (as CEO/Co-Founder)

Expertise & education

Expertise

Programmatic AdvertisingAd Exchange TechnologyReal-Time Bidding (RTB)Supply Chain TransparencyAdTech InfrastructureSustainability in AdvertisingCarbon Emissions MeasurementVenture-Backed Company Scaling

Education

  • B.S., Computer Science, Dartmouth College

Speaking topics

The history and future of programmatic advertisingSustainability and decarbonization of the ad supply chainSupply chain transparency and efficiency in digital mediaEntrepreneurship and company building in AdTechThe environmental cost of digital advertising

Recognition

Notable achievements

  • 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

Awards

AdExchanger's Most Influential Person in AdTech (multiple recognitions)Inducted into the AdTech Hall of Fame (industry recognition)

Publications

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