Former CEO (deceased) at OpenX
Six years leading OpenX as CEO, championing programmatic transparency and supply-path optimization in the open ad exchange ecosystem until his death from cancer in January 2026.
Last updated May 3, 2026 by jonholm
John 'JG' Gentry led OpenX as Chief Executive Officer from 2020 until his death on January 15, 2026, from cancer at age 58. He spent over a decade at OpenX, joining in 2012 and rising through executive roles before becoming CEO. Under his leadership, OpenX was one of the few independent supply-side platforms to remain influential against the walled-garden ad exchanges, with a focus on programmatic transparency, supply path optimization (SPO), and sustainability — OpenX became the first carbon-neutral ad tech company during his tenure. Before OpenX, Gentry held leadership roles at Spot Runner, Green Dot, Disney, and Overture, building over two decades of experience across digital advertising, payments, and consumer technology. He was widely respected in the AdTech community for his calm, principled leadership and for treating colleagues with humility and care — qualities his peers eulogized as rare in the industry. Gentry helped shape OpenX's leadership succession during his final years, and the board appointed Matt Sattel as CEO on February 5, 2026. Gentry left a public LinkedIn post for posthumous publication that read, in part: 'If you are reading this, it means that I'm no longer around and lost my fight with cancer. While I am dying earlier than most, I outlived myself by 28 years, thanks to a kidney transplant and modern medicine.'
OpenX (2020-2026)
OpenX (2012-2020)
Spot Runner (pre-2012)
Green Dot (earlier career)
Disney (earlier career)
Overture (earlier career)