Whether it’s a town hall gathering or face-to-face meetings at Alliance’s operations around the world, Heffernan is always talking with the company’s 20,000 employees.

“Actually, I love it. It’s the best part of the job,” he tells Fortune.

That personal touch is also a key reason behind Alliance’s success and Heffernan is credited with playing a big part in the company’s growth. He joined Alliance 20 years ago as chief financial officer and was responsible for engineering several critical acquisitions. Today, Alliance, based in Plano, Texas, has revenues of more than $7 billion and is ranked on Fortune’s list of America’s biggest companies. Many people may not have heard of Alliance, but the company knows a lot about them. It is a giant in the field of “big data” as it gathers information about consumers on everything from where they live to what car they drive and what they buy.

Heffernan, who became CEO in 2009, says the most critical leadership lesson he has learned is the importance of communication with employees. “I know it’s squishy and it’s more of a soft skill type of thing,” he says. “I am a believer that a well-educated employee is someone who can be much more productive.” He adds, “To ignore it, I think is folly.”