Banks tend to approach data-driven marketing as if it is the Normandy invasion-marshalling resources to build huge data warehouses and restructure organizations from top to bottom to "focus on the customer." But as important as these initiatives are, they must not detract from a bank's ability to act quickly and decisively. Modest applications of data- driven marketing are the best first steps to success, and examples like the one that follows bear this out. At a major retail bank, which will remain anonymous in this article, executives were certain that a newly created telemarketing center was vastly superior to branches for selling a range of banking products. Sales reports showed that telephone reps were achieving good sales rates.