Prior to Mindshare, Rowlinson, who has been at the agency since 2004, was group account director at Starcom Motive and also worked for Leo Burnett.
The WPP-owned agency said Rowlinson had made "a substantial contribution to Mindshare UK, as an effective member of the management group over the past four years" and that he "will continue to play a key role as part of the GroupM trading team".
Jed Glanvill, chief executive at Mindshare, said: "Paul has consistently pushed for the broadcast team to be ahead of the market and will take this approach to the wider Exchange team. He has an ambitious and exciting vision for the development of the department."
Rowlinson said: "Mindshare UK's Exchange team have a diverse skill set that I believe is unrivalled in UK media agencies.
"We are proud of our reputation for brilliant performance across every aspect of our service, are committed to continuing to modernise our product and will constantly be looking for new ways to enable our clients to harness the power of media to drive business results."
Zonfrillo spent 10 years at Mindshare before moving to GroupM. He has been responsible for leading trading for Mindshare clients including News International, Nike and Motorola.