Marketing can be tough to live with but dangerous to do without. Don't promote yourself and no one else might, either. But there are so many ways to stumble, whether it's looking for viral pick-up that will never happen or trusting forms of marketing that could turn around and bite you.

Like anything else, good marketing needs to sit on valid principles. One at the heart of good marketing is resonance. It's not enough to come up with a clever idea, talk about benefits for a customer, or even create what seems to be an overall witty idea.

Marketing is an issue of emotions. Talk to enough veteran marketers and you will learn something important: Virtually everyone makes decisions driven by emotions, not logic. Some people may have psychological quirks that cause them to act in a cooler, more rational manner. And there will be people who are making purchase decisions for a business role. They will lean more toward rational decisions, although even they can be heavily swayed by emotion.

When you want something or need something, it's an emotional connection. Marketers don't create the needs and desires. But they have to talk to them. If not, it's like trying to sell something and making your pitch in English when the prospect understands only Danish. No matter what you say, the other person isn't going to get it.

But emotions are tricky. You don't directly tap them, like a series of buttons to press so you can send a message. Emotions are something that are evoked and attracted. It's like the study of resonance in physics.

If you blow over the top of a bottle at the right angle, with the right speed and volume of breath, you hear a musical tone. The air in the bottle resonates to your action. Similarly, beautiful tones from a musical instrument owe to resonance. When luthiers choose wood for a violin or guitar, they may tap a blank with a rubber mallet and listen for the tone. Some pieces of wood have that potential tone. When they become instruments, they can ring in sympathy with notes played. That's resonance.

Marketing has to be the same, which is what makes it so difficult. To evoke resonance, you have to be connected somehow to the audience. There must be common humanity. In a way, at least a bit, you have to love the people you address. How else are you going to be on a sympathetic emotional note? Anyone can pitch, but truly great marketing goes beyond what can fall short as manipulation and lies. You have to touch emotional truth.

It starts with empathy toward the audience, but doesn't stop. What words do you use and what is the emotional sense of each? Is there something truly positive to say about your product or service? If not, all you can do is lie and your marketing will be less than mud.

When I think of great marketing, I look at some classic examples. There's the famous early 20th century campaign "Do You Make These Mistakes in English?" A correspondence school, at a time when people often never got through high school, let alone college, offered instruction. Copywriter Maxwell Sackheim wrote the ad and the copy for a campaign that literally ran for 40 years. It was based on understanding that the audience was insecure because the people knew the improper use of English could lock them out of opportunities. You could say it was opportunistic, but Sackheim understood the pain people felt.

In the late 1950s, advertising great David Ogilvy won the Rolls-Royce account and created many versions of an ad headline. The winner, picked by other writers at the agency, was based on a single line an engineer from the company had written in a technical document: "At 60 miles an hour the loudest noise in this new Rolls-Royce comes from the electric clock." Ogilvy understood the way people who could afford a Rolls felt, the desire to feel insulated and at peace.

Hitting an emotional resonance doesn't mean wearing your company's heart on a sleeve. It also doesn't come from foggy inspiration. It requires hard work, research, and putting yourself into someone else's place. When you hit those just right, your marketing will be a hit with the audience.