New concepts are constantly emerging in marketing. We’ve seen the rise of “green” marketing, appealing to people’s environmental concerns, and mobile marketing, finding new ways to get the attention of potential customers clutching hand-held devices.

There’s a lot to be said for new strategies, but it sometimes seems people get dazzled by novel approaches. They forget there’s one enduring strategy that never fails.

Honesty.

You can only tell customers and prospective clients so many times about who and what you are. At some point, you have to show them. And if the experience you provide doesn’t match how you’ve represented yourself, your company, your service or your product, they’ll not only walk away – they’ll likely take others with them.

There are a lot of ways your honesty – or lack of it – can be revealed in the course of a day. Sometimes, it may seem like the price of being honest is just too high, for instance when you’ve made a mistake you fear will seriously damage your reputation. Do you own up to the mistake? Blame someone else? Cover it up?

I like Jason Fried’s answer.

Jason is the cofounder of 37signals, a company that produces a chat tool called Campfire for small businesses. A couple years ago, he wrote a column in Inc. magazine about what happened when Campfire malfunctioned, sparking a real wildfire of rage among his customers.

He wrote, “People don’t judge you on the basis of your mistakes – they judge you on the manner in which you own up to them.”

Jason and his business partner were honest about their mistake, and sincere and consistent in their apologies. They corrected the problem, of course, and also gave their customers a free month of service for the disruption.

By the end of their nightmare, Jason and his business partner were getting messages like this from their customers: “37signals has been giving a free lesson in customer service and honesty the past few weeks.”

While I don’t believe anyone reading this would intentionally lie to customers or in their marketing, there are many situations that test us. I find it helps to have the rules of engagement firmly in place before a situation arises.

Here are a few good “old-school” marketing strategies:

• Be honest about what you can do – and what you can’t. I’m a “yes we can” kind of businesswoman. I’ve succeeded in business because I know there’s almost always a way around an obstacle if you’re flexible and creative in problem solving. I don’t back down from a challenge just because it’s something I’ve never done before. However, I also know there are some things I cannot do.

Recently, I had a prospective, high-profile client who would’ve been a dream to bring onboard. In our many conversations, he talked about the kind of publicity he wanted and the general goals he hoped to meet. I knew we would have no problem getting him what he was looking for. But then, just as he was preparing to sign the contract, he shared what he really wanted: his own regular segment on a national network morning show.

To get that he would need more than a publicity campaign, so it’s unlikely we could make it happen for him. And I was honest about that. He didn’t sign on with us, but, more important, we maintained our integrity and he was not disappointed.

• Keep your word. If you offer a “money back guarantee,” honor it upon request. If you say you’ll have something done by a certain date, move heaven and earth to meet the deadline. If for some reason you can’t, let the customer know, explain why and be prepared to help mitigate the consequences if possible. The corollary rule on deadlines is, don’t promise more than you can deliver.

• Remember, there’s a fine line between attention-getting and trickery. In marketing, the competition for attention is overwhelming, so we draw upon all of our creativity to make ourselves stand out. That’s fine. Tricking people is not. In fact, some tricks – like the old bait-and-switch tactic – amount to fraud. Others may not have legal consequences but can be just as damaging.

I’m thinking of the congratulatory emails LinkedIn sent out, telling members, “You have one of the top 10 (or 5 or 1) percent most-viewed profiles for 2012.” Many recipients were pleased and rushed to share their exclusive ranking on social media. Many weren’t so pleased when it was reported that millions of other members also got the emails.

It boils down to the Golden Rule for business: do unto your clients, customers and prospects as you would like done unto you. Sometimes, it requires really hard decisions. But in the end, integrity is the most valuable marketing tool in your arsenal.