Recent posts by my colleague Bill Merklee have discussed the pros and largely cons of using humorin advertising. The basic tenet is that it doesn’t work if too many people don’t “get the joke.”  I’d argue humor in advertising doesn’t work for a bigger reason – advertising is serious business. People want to find something that you’re hopefully selling.

One key to advertising is catching someone’s attention – hence the attraction of humor.  It’s also the reason frequently for skimpily clad girls, six-pack bare-chested men and celebrities in ads.  Sex and celebrities grab our attention. However, getting attention and having a message resonate are two very different things.

The reason ad-men have bad reputations and most ads don’t work is very simply that they don’t keep their promises. A promise not kept in an ad is a scam and you know the old saying: “Fool me once…”

The most basic reason for an ad is to make a promise. You advertise to tell someone that you have a product or service that will do something for the consumer. Heaven help you if you don’t have that product or service and if it’s falsely advertised in terms of what it promises to do.

Unfortunately, false promises are more common that one would hope. In one recent example, a retailer took a stock photo of a garment and put it in her ad. The good news is that the ad worked and people walked into her store with the ad in hand and asking for the item. Oops. The retailer never carried that particular item and couldn’t fulfill expectations. Sure, she tried to steer people to similar or different product she did carry, and also tried to quickly order the pictured garment, but the promise was broken particularly for those who hurried in to be first to buy.

What’s the promise in your ad? If you can’t easily say, there’s a problem right there. If you can, but feel unsure if it’s solid, that’s yet another problem. Make sure your ad firmly makes a promise you’re comfortable keeping. Promises can range from lowest price to largest inventory, punk trendy, get this one great outfit, get a James Bond car here, or find your closet full of coolest stuff. Then when targeted customers respond, they will never be disappointed.

The Walk-away: Great advertising makes a promise so compelling, targeted customers can’t help but respond. But like first impressions, consumers will only trust you once, so make sure you can fulfill the dream you promoted in your effective ad, or you’ll have trouble attracting repeat business.