New York—Media giant VNU and the In-Store Marketing Institute on Thursday announced a partnership to introduce a global measurement service designed to help marketers better understand how to reach and influence consumers while they are in the store and deciding what to buy. The new service will build on the effort of P.R.I.S.M. (Pioneering Research for an In-Store Metric), which was launched earlier this year by a consortium of retailers and manufacturers, including 3M, Procter & Gamble Co. and Wal-Mart Stores, and led by the In-Store Marketing Institute. The P.R.I.S.M. Project provides retailers with a common language for measuring in-store consumer reach. A new unit of VNU, Nielsen In-Store, will measure consumer exposure to various in-store marketing vehicles, such as television, radio, shelf talkers, digital signage and other point-of-purchase displays. All told, these in-store marketing efforts make up the sixth-largest ad vehicle in the U.S., with $18.60 billion in spending in 2005, according to VNU.