Last spring, Scott Heintzeman, CIO of Carlson Marketing , and his staff were developing new business intelligence systems. The project would support Carlson’s marketing business unit 1to1, which helps clients mine their customer data to create individualized direct-marketing materials. Carlson executives expected the business unit—a new line of business within the company—to be one of its top performers. Heintzeman knew he had to deliver, but he couldn’t do it on his own.

Heintzeman was not worried about the technology needed to support the unit. He was more concerned that 1to1 lacked a strong business leader—someone aggressive enough to establish business processes and rack up some quick wins, while personable enough to help employees through the inherent stress and uncertainty of a new venture. Heintzeman believed he knew someone who was right for the job: Janet Sparkman, the general manager of Carlson’s Gold Points Reward Network, a customer loyalty program that is one of Carlson’s core businesses. Heintzeman had worked with Sparkman previously and they worked well together. So he asked Sparkman to consider a job change. She flatly declined.

That’s when Heintzeman went to work, lining up support for his plan among other business leaders and assembling a dream team within IT to support Sparkman. He knew what attracted Sparkman to new ventures: “Janet isn’t going to join something that she cannot win,” Heintzeman says. “No way would she make that change if she did not have the right IT team to support her.”

Heintzeman’s initiative to weigh in on a strategic business issue is familiar to any executive but particularly challenging for CIOs, who have little formal power, observes Susan Cramm, a former CIO of Taco Bell who is now an executive coach (and a CIO columnist). Often, a CIO’s impact comes down to how good she is at convincing business leaders and end users—who don’t have to listen to her—to follow a strategy that the CIO deems important. “The ability to ‘lead from the back’ becomes essential for success,” says Cramm. “Without influence skills, CIOs are relegated to being order takers.”

To have influence, it’s not enough to be able to explain IT in an easy-to-understand way. To sway opinions and convince others to act, CIOs need expert knowledge of their subject and its relationship to the business, the ability to adapt their message to how their audiences like to learn, access to allies who will support their goal and the ability to vet ideas in a nonthreatening way.