WPP has taken the top spot as the biggest marketing group, displacing Omnicom.  WPP experienced a 13 percent increase in revenue following the 2008 acquisition of TNS, growing from $10.7 billion in 2008 to $12.1 billion in 2009. Omnicom, on the other hand, saw a decrease of 12 percent from $13.4bn to $11.7 for the same time period.

Publicis came in third and IPG in fourth.