A pioneering programmatic media executive who became GroupM’s first Chief Digital Investment Officer in 2012 has died. MediaPost reports that Ari Bluman died May 25 after a long illness. He was 44.

“Bluman, who spent most of his career at 24/7 Real Media and rose to the role of president-North America for its Real Media Group operations before joining GroupM, is known for helping to restructure the digital media-buying marketplace by pushing clients and the industry at large away from open exchanges and more deeply into private marketplaces where big agencies like GroupM and its clients have greater leverage, visibility and control against things like ad fraud,” the story reports.

In a memo announcing Bluman’s death, GroupM Global CEO Irwin Gotlieb wrote: “Ari’s contribution to our business survives him. His work on bringing order to chaos in digital marketing led the industry and created unique value for us all. Ari was a pioneer and innovator, brashly demanding higher standards, better performance, and accountability. He did this not to benefit himself, but to improve the industry he loved and helped to create. Ari changed the lives of literally thousands of people in our industry who attribute their success to his principles and his relentless pursuit of truth in digital advertising.”