Since the introduction of point-of-sale scanning in stores in the 1980’s, item-level sales data has been retail’s best proxy for consumer demand. But today’s retailers can’t wait for changes in demand to be reflected in sales to react. Reducing lag time to reaction has become Retail’s Holy Grail. The good news is that via their digital activities, consumers are generating a huge number of pretransactional signals that have the potential to give retailers insights to emerging demand patterns, so that they can adapt to meet them head-on. But to move beyond being reactive to becoming an adaptive retail enterprise, retailers must be able to manage unprecedented growth of new kinds of data and derive meaningful insights from it.