Nancy Hall , a media-buying executive who has cultivated a specialty in data and ad tech, has been named CEO of the U.S. operations of WPP Media, putting her at the helm of one of the most influential agencies in the media and entertainment sectors. WPP Media controls billions of dollars on behalf of major advertisers and helps determine where that money should go and how it should be spent. “Nancy’s unparalleled background and visionary leadership make her the definitive choice to lead WPP