(FORTUNE Magazine) – WHEN SUE NOKES JOINED T-MOBILE AS senior vice president of customer service in 2002, the cellphone company, based in Bellevue, Wash., had a little problem: Lousy customer service was driving T-Mobile users crazy. Calling with a question or complaint, they got put on hold for what seemed like eons, then spoke with customer-service reps who weren't much help. J.D. Power's customer-satisfaction surveys ranked T-Mobile dead last in the industry, trailing Verizon, Cingular, Nextel, and Sprint. So much for its ad slogan: "Get more." Nokes launched a total overhaul. The first step: getting T-Mobile's human resources people and its marketing department to sit down and talk. The idea was to revamp the company's hiring practices, thus increasing the odds of picking customer-service staffers willing and able to follow through on the marketing mavens' promises.

Sounds like common sense, doesn't it? But surprisingly few companies do it. "We call the gap between HR and marketing the 'white space' in organizations," says Don Schultz, founder of a think tank at Northwestern University called the Forum for People and Performance Management. "The customer-contact people don't report to anyone in marketing or have any contact with them." Neither does anyone in HR, so HR isn't able to put customer-service people in place who can deliver on the marketers' message. Northwestern's latest research (see ROI of Integrated Marketing at www.performanceforum.org) shows that both HR and marketing managers are well aware of the white space: "We started studying this because people from 40-odd big companies like Honeywell, GE, and AT&T asked us how to fix it."

At T-Mobile a new set of hiring criteria emphasized traits like empathy and quick thinking. Then Nokes set up a rigorous evaluation process. "In our business, customers want their problem resolved fast, in one phone call--and courtesy matters," she says. "So we created a system that gives a lot of weight to those two elements. And we made sure that everyone knows exactly how he'll be evaluated." Both Nokes's experience and the Northwestern study suggest that when HR and marketing are in sync, employee-incentive plans work. "Everything we do is linked to a common message and a common theme," Nokes says. She started an employee-rewards program called Do More, Get More, which bestows restaurant dinners and exotic trips on workers who meet stringent standards for courtesy and speed. "Some see this stuff as 'fluff' that just drives up costs," says Nokes. And she's the first to admit that in and of themselves, incentives are no panacea: "The biggest mistake I've seen companies make is going after only one piece of the pie--trying to improve customer service by focusing on hiring alone or training alone or incentives alone. But it's an end-to-end process. It won't work unless you do the whole thing." She says that in the past two years attrition and absenteeism have dropped 50%, while productivity has tripled.

And what do T-Mobile's formerly exasperated customers think? Here's a clue: J.D. Power has ranked T-Mobile No. 1 in customer service for two years running.