Wal-Mart taps Golin Harris, Cohn & Wolfe and Porter Novelli for PR

“After a lengthy agency review for its multimillion-dollar consumer-PR business, Walmart has selected Interpublic Group of Cos.’ Golin Harris, WPP’s Cohn & Wolfe and Omnicom Group’s Porter Novelli,” industry sources told Advertising Age ’s Michael Bush. Why three agencies? To drive down costs, naturally. According to Bush, “The three agencies will bid against one another for individual assignments in the retail giant’s effort to drive greater cost efficiencies.” Edelman will…