Best Buy's in a tough business. The electronics giant ($50 billion in 2010 revenues) competes with Amazon, the best of the online retailers, and Walmart, the world's biggest bricks-and-mortar retailer. The company's shares have fallen lately.

What's Best Buy's competitive advantage?

It's the people in the blue shirts, says Brian Dunn, Best Buy's chief executive. "Our business is utterly dependent upon getting those 180,000 people aligned and moving forward," he says.

This is why sustainability is important to Best Buy, the 51-year-old chief executive says. It's about providing those people with opportunities, making sure they are heard and showing them that Best Buy cares about them and their values.

Brian gave the keynote speech this morning at the Boston College Corporate Citizenship Conference, which is being held in Minneapolis, Best Buy's home town. We spoke briefly after his talk, which wasn't your typical speech about sustainability or corporate responsibility. I don't believe he mentioned the words "carbon footprint." Instead he talked, in a personal way, about Best Buy's people, their aspirations, how they connect to sustainability and how he connects to them.

Providing an inspiring, engaging workplace is "the No. 1 element of Best Buy's sustainability strategy," Brian said. "We are leveraging our people as a competitive advantage. We stand on the shoulders of all the people who have worked on the floor for the past 40 years at Best Buy."

This not only sounds good but makes business sense: Just try getting help from Amazon or Walmart if you can't figure out why your TV or computer isn't doing what you want it to. In a commodity business, what makes Best Buy different is (or needs to be) service.

Of course, all CEOs mouth platitudes about how people are their company's most valuable asset. Brian is different, I think, because of where he came from -- he began his career at Best Buy as a salesman, 26 years ago. "This is personal to me," he says. He knows that selling boxes isn't a glamorous job. "Working in retail is tough," he says. "It's the monotony." So he wants to help Best Buy's people to connect their work to a larger mission that matters to them. He told a story about a Mexican-American worker in Las Vegas who wants to help his relatives get hired as Best Buy expands into Mexico, and another about a woman who used Skype connections to talk with her husband, a soldier stationed overseas.