Marketing is a delicate art: Your goal is to influence people's thinking and choices, but it's easy to do more harm than good.

However, you can lower the odds of your marketing efforts going wrong if you avoid five deadly sins. That's the word from Jonah Sachs, founder of Free Range Studios and author of Winning the Story Wars.

Fittingly, he offers a story for each of the sins to illustrate why it's bad:

1. Vanity

The ancient Greek story of Narcissus illustrates this sin, Sachs says. Narcissus, the handsomest hunter in the land became so entranced with his own reflection in a pool that he either remained immobilized there forever or fell in and drowned, depending on the version of the story.

For modern-day marketers there may be an even bigger risk: being ignored. "It's hard to tell a story when you're the main character and everything else is a background for your character's greatness," he says. "You're going to sound largely irrelevent to audiences who hear 3,500 marketing messages a day." A better approach, he says, is to create a story where the customer (or someone just like him or her) is the hero.

2. Authority

In the story of the Emperor's New Clothes, by Hans Christian Andersen, the emperor relies on the authority of his tailors who assure him he is clothed in cloth so fine only the wise can see it. Too embarassed to admit that he sees nothing there, the emperor eventually finds himself nude in front of all his subjects.

The problem with relying on authority, whether subject matter experts or facts and statistics is two-fold, Sachs says. First, experts have been so flamboyantly wrong about so many things (remember the doctors who swore in the 1960s that smoking was safe?) that the public is instinctively mistrustful. Worse, by relying on facts you miss the chance to make a more heartfelt connection with customers. "If you can reach people on emotion and values, that's a more powerful way of getting them marching toward you," he says.

3. Insincerity

Remember the story of the wolf in sheep's clothing, one of Aesop's fables? A wolf who comes upon a sheepskin, puts it on, and hides within a flock. But the disguise works too well and the shepherd, mistaking the wolf for a sheep, slaughters him for his own dinner.

For modern marketers, the big risk of insincerity is getting found out. With the Twitterverse, Blogosphere, and Yelp out there, it's fairly difficult to fool anyone for long. Fiji Water ran smack into that problem, Sachs says, when the company attempted to lure environmentally conscious consumers to its obviously high-carbon-footprint product by claiming it would use offsets to become carbon negative. But closer examination of Fiji Water's plan revealed that it was calling itself carbon negative by giving itself credit for future actions the company claimed it would take over the next 30 years! Not surprisingly, this resulted in a lawsuit and the kind of bad publicity that likely left Fiji Water wishing it had skipped the whole thing. "You want to reach out to a new audience but you can't deliver on that promise," Sachs says. "Better to be true to yourself and have people come to you."

4. Puffery

The down side of pretending to be bigger than you are is displayed in this unforgettable line from "The Wizard of Oz": "Pay no attention to the man behind the curtain."

"The idea is that we can speak in the disembodied voice of God and have people listen, rather than finding our unique and human voice," Sachs says. "Finding that human voice is a step that marketers so often miss." It's an especially important step for small businesses, he adds, whose customers particularly want to see the human beings behind the products.

5. Gimmickry

Sachs illustrates this sin with the tale of King You of Zhou who repeatedly calls out his warriors on a false alarm to coax a laugh out of his hard-to-amuse trophy wife. You can guess the rest: The kingdom actually does come under attack so he lights the distress beacons but the warriors stay home, believing it to be another gag.

There's nothing wrong with being funny, Sachs says, but trying too hard to be funny can backfire--which is why, he says, most Superbowl ads aren't very effective at selling their products. "It's great to use emotion and humor to connect with your audience," he says. "But if you jump right to 'How do I make this funny?' you can wind up bending over backward to make that connection, and you can undermine your message and your brand."