GroupM is the world’s largest advertising media company in terms of billings. It is headquartered in New York City with over 21,000 employees and 400 global offices in 81 countries. GroupM was formed in 2003 by WPP Group to serve as the parent company of WPP's media agencies including Maxus, MEC, MediaCom, Mindshare, QUISMA, Xaxis, Outrider, Catalyst, Kinetic, Quasar, IEG, Movent, Vocanic, Agency M and Plista.