One of the most effective business-to-business ad campaigns of a generation ago was built around the concept that nobody ever got fired for recommending IBM. At the time, new computer companies were springing up left and right, offering promising but unproven technology. IBM may not have been exciting, but it was considered to be the safe choice.

What made the campaign effective was not what it said, but what it implied. IT managers and other corporate executives read the ads and thought, “They’re right. If I recommend one of those other companies and the technology doesn’t work, I’m going to get the blame. IBM may cost more, but everybody knows and trusts them.”

In other words, the savvy creatives at IBM’s ad agency were tapping into one of the most powerful emotions: fear. Along with its younger brother, doubt, fear can be an incredibly strong motivator. You don’t have to terrify or threaten people – in fact, that usually backfires. All you have to do is trigger the doubt and fear lurking inside them, and they’ll come to the conclusion you want on their own.

Want to sell a security system? Make them think about what a burglar could do. Want them to specify you instead of a competitor? Follow IBM’s lead and sow those seeds of career doubt. Or you can even take the approach used by my favorite headline of all time: “Nobody ever died from eating OUR product.” (Okay, it appeared in Mad Magazine, but it was still a beaut.)