Other benefits of the partnership include joint approaches to mutual clients and joint technology development, including the integration of Omniture and WPP data and products.
Sir Martin Sorrell's WPP and Omniture will also share marketing insights and consult on best practices, and 500 WPP employees will be trained on Omniture products within the first year of the relationship.
WPP companies involved include G2, OgilvyOne, RMG, Wunderman, Enfatico, specialist agencies Schematic, VML and Zaaz, Group M, 24/7 Real Media, Kantar and Bridge Worldwide.
Sorrell said: "In the current economic environment, and as clients continue to experiment with and develop their online budgets, the need for better analysis, measurability and focus on return on investment is more important than ever.
"This partnership will help our many mutual clients meet these objectives by equipping WPP agencies -- across all geographies and disciplines -- with the capabilities and tools needed to customise and deploy Omniture solutions in the most efficient and effective ways."