Loyalty is important to Stuart Aitken, CEO of downtown-based dunnhumbyUSA.

It's central to dunnhumby's mission of personalizing customer relationships with its big retail and consumer brand clients such as Kroger Co., Macy's and Procter & Gamble Co.

It's vital to fostering a workplace culture for dunnhumbyUSA's employees that has earned it recognition as one of Fortune Magazine's "Great Places to Work."

And it's critical to the City of Cincinnati, which is turning over a prime piece of downtown real estate at Fifth and Race streets for the company's new headquarters.

"Look at us, we're a small company, and we've been treated incredibly well by the city," says Aitken, 41.

In just 10 years since dunnhumbyUSA was formed as joint venture of the Kroger and London-based dunnhumby Ltd., employment has grown from just three employees to 600. It's one of Cincinnati's fastest growing companies, adding 10 employees a month, and it has become a showpiece as the type of cutting-edge consumer brand and marketing companies city and state officials want to attract.

Great Location, Employees

Aitken sees plenty of positives for growing a business here. He says it is a mistake for young businesses to move to places like New York, Chicago or Silicon Valley.

"It's very easy to become a minnow in places like that. We would have. Here, you can make a name for yourself and get great employees to come to work for you."

In an era of mass marketing and big box retailing, dunnhumby is a leader in using customer purchase information from loyalty cards and other sources to personalize the customer's experience with the retailer or the brand.

"The analogy I like to use is think of customers being in a large bucket," says Aitken. "A lot of companies focus on turning on the faucet to add more customers to the bucket, but our focus is on plugging holes in the bucket and getting existing customers to buy one more item, one more time," he says.

"The customers you do have are shopping you. They are loyal to you as a brand or a store. How are you being loyal to those customers?"

Mining the Data

The firm starts with masses of data from more than 400 million households in 28 different companies. Using sophisticated mathematical models, dunnhumby's analysts parse the data to develop specific recommendations for its clients on a variety of things including product assortment at specific stores, pricing, weekly ads and promotions. In Kroger's case, dunnhumby develops personalized monthly mailers with coupons for items that customer has previously purchased.

Started in 1998, dunnhumby (the name is a marriage of the company's husband and wife-founders Clive Humby and Edwina Dunn) got its first big break in 1995 when it developed a highly successful loyalty card program for Tesco, one of the world's largest retailers and the largest grocery chain in the United Kingdom. The parent company has 2,000 employees in 33 offices around the world.

Kroger, the largest U.S. supermarket chain, launched its Plus card loyalty program in 1999. It went looking for a way to leverage that information and found its way to dunnhumby Ltd. It formed the joint venture with the London parent in 2003. With more than 160 U.S. clients, the joint venture's revenues exceed $275 million.

Kroger has attributed much of its recent growth to the "customer first" approach fostered by the joint venture. Kroger CEO David Dillon has called dunnhumby the supermarket chain's secret weapon. Its customer insights have helped Kroger string together an industry-leading 35 consecutive quarters of higher same-store sales.

More Competition

As dunnhumby has become more successful, it has spurred more competition.

"We're seeing a lot of big consulting firms wanting to do what we do," says Aitken.

One way it sets itself apart is by developing exclusive relationships with its clients.

For example, dunnhumby works with Kroger but not Meijer; Macy's but not JCPenney.

"The reason is we're trying to help our client win versus helping everyone win in the market. We believe this is a competitive advantage and one we value."

It allows clients to share their strategies and goals more than they would with a consultant. "We are joined at the hip with Kroger," Aitken says.

At the same time, Aitken says the company is sensitive to the growing fears about firms aggregating large amount of personal data and how it's used.

"Everybody here is dealing with numbers, not with names and addresses," he says. "That's vitally important to us. This is our business. If we betray the customer, it's over. The most important thing for us is keeping identity and information completely secure."

Cultivating talented employees is also critical to growing the business, Aitken says.

Employees are rewarded with perks that have put dunnhumby on Fortune's Great Places to Work list.

Those include giving employees their birthday off, five weeks paid vacation, and monetary awards after 5, 10 and 15 years of service. The company's current offices in a former warehouse at 444 W. Third St., on the edge of downtown, are bright and open with no private offices (even for Aitken). It includes a cafeteria, fitness rooms with showers, and even provides bicycles employees can borrow to pedal to meetings downtown.

Eclectic is Best

While dunnhumby has its share of mathematicians and statisticians, Aitken says he loves to recruit people with eclectic backgrounds

"I don't want people who are just going to hand over a report to a client. I want people who have opinions "” people who believe they can change how our clients think and act," he says.

"Taking risks on people is huge. Giving people the opportunity is huge. They will go out of their way to prove you right," he says.

He's learned that first hand.

After growing up in working-class Glasgow, Aitken earned bachelor's and master's degrees in information management. He worked at a series of IT jobs, including an attempt to crack Silicon Valley ("I failed miserably") before taking an information technology job at giant West Coast supermarket chain Safeway.

It was there that he was offered a job in Safeway's marketing department. Against his supervisor's advice, he took the marketing job and ended up managing Safeway's loyalty and strategic marketing and product categories.

"I believe eclectic experiences are incredibly important and give you a more rounded perspective on work and life. For me, the worst thing you can do is say: What if?"