Johnston (pictured) joins from GroupM’s Mindshare where he was global chief digital officer, as well as the global CEO of its Fast business unit.

He has been involved in digital marketing since its birth in the 1990s, when he joined the industry’s first digital agency, Modem Media. After Modem was acquired by Publicis in 2007, Johnston joined WPP and GroupM’s Mindshare.

Based in London, Johnston will report to Rebekah Brooks, CEO of News UK, which acquired Unruly in 2015.

Brooks said: “Norm’s data-driven approach and deep understanding of marketers’ requirements will be invaluable to Unruly clients and the wider News Corp business. He’s a programmatic pioneer with truly global experience.

“I am deeply grateful to Sarah Wood and to her co-founders, Scott Button and Matt Cooke, for their commitment to transforming advertising for the better. They have built Unruly into a scaled and trusted advertising platform and I look forward to Sarah chairing the Unruly board.”

Johnston, added: “Unruly is a company with its own vibrant culture and great potential in a fast-moving marketplace. The ad industry needs leaders like Unruly.”