AmEx customer service in action by Geoff Colvin @FortuneMagazine April 19, 2012, 9:00 AM EST E-mail Tweet Facebook Google Plus Linkedin Share icons FORTUNE — Jim Bush sees to it that when a customer calls American Express AXP , the person who answers engages in unscripted conversation. What makes that conversation productive is a staggering amount of data. A credit card company, through its awareness of customer spending, possesses deep knowledge about each customer’s life. AmEx’s great challenge and opportunity is to apply all that knowledge in ways that create maximum value for customer and company. The AmEx employee who answers a call sees a computer screen filled with data about the customer — name, age, address, what he tends to buy and where, plus payment patterns. The employee is trained to use that information in guiding the conversation. If the employee can discover a customer need that could be met by an AmEx product or service the customer doesn’t know about — “that has the most powerful marketing benefit to us of any marketing communication or marketing channel,” says Bush. Also on the screen is an indication — how it’s calculated is proprietary — of the likelihood the customer will leave, plus any early-warning signs that the company’s analytic software may have uncovered indicating that the customer is about to leave. The call-center employee is trained to dig for the underlying problem and try to solve it. Like most companies, AmEx hates customer churn, which has declined since Bush overhauled customer service. AmEx’s analytic software also calculates a predicted economic value of each customer. “That economic value is driven by engagement and loyalty,” says Bush. A customer who’s likely to stay with AmEx for decades is enormously more valuable than one who leaves after a year or two. That’s why Bush has reoriented AmEx’s customer service to use data to deepen customer relationships rather than to make customers’ phone calls go faster. Back to: How can American Express help you? This story is from the April 30, 2012 issue of Fortune.