The most valuable type of marketing is one you can’t buy. Yes, it’s more powerful than expensive TV commercials, more effective than full page newspaper ads, and packs more punch than 100 Google ads.

We are talking about World of Mouth. It’s when one friend tells another. Called WOM for short, this most primitive type of marketing is by far the most effective.

Why?

Because you may not pay attention to or believe an ad, but you always listen to your friend. And you most likely believe what your friend says.

If your BFF Courtney swears Sears is the best store in town, has the best selection, and features surprisingly low prices – you are going to give the Sears store a strong second look. You very well may drive over to the nearest Sears and stroll their many isles.

Would an expensive commercial make you do that? Probably not. But an urgent appeal from a trusted friend has a special power. It can make us pay attention, make us think, and cause us to act.

Here are 5 ways to make WOM work for you:

1. Offer customers a reward for their referral. Tell a friend and get 15% off with your next visit. Telling a friend is WOM. Even though your customer is essentially being paid to say something good about your store, their word is golden in the ears of a friend.

2. “The customer is always right.” We’ve all heard this bit of marketing strategy over and over. It’s been used to much that many customers think it’s a rule of good business.

But the real reason the customer is always right is it keeps BAD word of mouth from damaging the brand. Studies show when a customer has a bad experience, up to 100 people eventually hear about it through WOM. Considering the extraordinary power of WOM, it makes a lot of sense just to give the disgruntled customer a refund, free item, or exchange. That can turn bad WOM into good.

3. Do something extraordinary. Have an outrageous promotion, post a ridiculously low price, or introduce an exceptionally innovative product. Customers like to tell others when the news is just a bit shocking or surprising. This can spur WOM like nothing else.

4. Keep in mind print and web ads and broadcast commercials get most of their power from WOM. One person sees the ad, then tells another about it. That person may tell another creating a chain reaction that eventually reaches dozens of people. Communication scientists call this Multi-Step Flow. It’s surprising very few of us ever think past the initial person who sees the ad, but the reach can be far larger. That is especially true in the current age of Social Media. An experience can be posted to reach thousands of friends.

5. Do something nice. Give two extra donuts, fix the flat for free, throw in some designer sunglasses. This something extra can get people talking and telling friends about your kindness and their good fortune.

Now that you have a good feel for World of Mouth, think of some ways your business can create some. It’s far and away the most powerful type of marketing available. And it’s almost free!