Throw away what you know about marketing-the three-step mental model of stimulus, point of sale, and experience has changed. Google and Shopper Sciences studied 5,000 shoppers to find where shoppers switch from undecided to decided. In between stimulus and point of sale, we discovered decision-making now includes extensive research. Consumers go online to read reviews, comparison shop, look for deals, and more. Marketers that reach consumers here-the Zero Moment of Truth-will gain a true competitive advantage.