ClickZ: Solve Marketing Channel Conflict

Eric Picard started a series on a now-classic conundrum within online marketing: How do you credit a sale when more than one of your online media elements was exposed to the same buyer? Many companies are looking at high initial ROI figures, but then learn that many of those "transactions" are being double counted between the email, banner and search campaigns. It gets really hair when they start considering non-online media in the mix as well.