The CEO talks to Campaign after WPP's revenues grew less than 1%.
Appointment of Channel 4 CMO to top job is likely to be seen as a surprise because he has not worked in agency sector.
North America saw revenues fall by 2.7% for the year, while APAC, Latin America, Africa, Middle East and Central and Eastern Europe grew organic revenues by 3.7%.
Using fewer freelancers has improved margin and saved nearly $133 million.
A string of senior executives from outside Japan have departed after Wendy Clark and Jacki Kelley left.
Campaign reports from capital markets day where WPP presented to investors.
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