it's the biggest media conglomerate in the world
here's the group acquisition history
http://www.wpp.com/WPP/About/WhoWeAre/History.htm
Ogilvy & Mather Worldwide (奧美全球)
Ogilvy Direct
Ogilvy Public Relations Worldwide
MindShare (傳立媒體)
Batey (百帝廣告)
J. Walter Thompson Group (智威湯遜)
Shanghai Advertising Agency
H-Line Worldwide (China)
Era Public Relations (Taiwan) (21世紀公關)
AGB Nielsen Media Research (尼爾森媒體研究)