Lollback calls time on GroupM CEO role Former chief marketing officer says he plans to return to his client-side marketing roots to pursue new professional opportunities Mark Lollback Mark Lollback is calling time on his GroupM CEO role at the end of this week after a five-year stint at the helm of the WPP AUNZ media business. Lollback joined GroupM in April 2016 after working as a local and global marketing leader for brands such as McDonalds, Unilever and ANZ Banking Group. His role at GroupM saw him overseeing integration between the group’s portfolio of agencies including Mindshare, MediaCom, Wavemaker and Essence as well as the debut of the Finecast addressable TV business.