• by Joe Mandese  @mp_joemandese, June 15, 2010

In an important sign of support from Madison Avenue, Arbitron just announced that WPP's GroupM unit has signed a multi-year contract for Arbitron's portable people meter and diary radio ratings services across all the markets they measure.

"Our clients need high quality measurement tools to guide their media buying strategies and help track the return on their investments," Lyle Schwartz, managing partner-director of implementation research & marketplace analysis at GroupM stated.