New York-based trend and research company PSFK has launched PurpleList, a Quora-like question and answer service for marketers staffed by 750 invited industry experts from around the world including Foursquare Founder Dennis Crowley, Engadget Founder Peter Rojas and Treehugger FOunder Graham Hill.

New York-based trend and research company PSFK has launched PurpleList, a Quora-like question and answer service for marketers staffed by 750 invited industry experts from around the world including Foursquare Founder Dennis Crowley, Engadget Founder Peter Rojas and Treehugger FOunder Graham Hill.