If you're not engaging your customers to make them ambassadors for your company, you're missing out on one of the most potent marketing strategies there is. So says Bill Lee, author of The Hidden Wealth of Customers.

"In today's world, traditional marketing is increasingly irrelevant," Lee says. "Buyers ignore it or don't trust it. They're using their own resources to check you out--their colleagues, friends, neighbors, professional associates, etc.--their peers. You have one resource that is peer to the buyer, and it's not your sales people or copywriters or ad agencies. It's your customers. You've got to get them marketing and selling for you."

Sounds great, but how do you go about it? Lee advises these four steps:

1. Create an excellent product or service that customers truly appreciate.

If you skip this step, the rest of the steps won't work.

2. Select one or more potential rock star customers.

They may not be who you think they are. Company leaders often assume that their rock stars are their most loyal customers, or their biggest customers, or the best known brand names. But loyal customers may or may not be willing to promote you. The biggest spender may not be a profitable customer for you, and the big brand names often have corporate policies against endorsing other companies.

Instead, look for loyal customers who have a good story to tell about how your product or service helped them, and who are eager to tell it. "They should have access to influential networks that contain more buyers like them. And they should want to build their reputation and influence in such networks."

3. Turn your customers into stars by giving them what they want.

Create rock stars by helping them build their own social capital. One way to do this--and something every company should do--is to create a formal or informal advisory board and invite your potential rock stars to join. That will give them a chance to network with your team and also with their own peers.

Look for ways to give them visibility within your industry, for instance by having them write guest posts for your blog or creating case studies with them. Not only will that highlight the benefits of your product or service, but it also highlights your customer as an expert voice.

4. Whatever you do, don't give them financial incentives.

"The biggest mistake companies make with customers is thinking they should rely on rewards, discounts, or other incentives to encourage them to become advocates," Lee says. "This is a vestige of applying traditional marketing techniques to customer advocacy."

It's likely to backfire, leaving both customers and prospects feeling uneasy about what seem like bribes, he warns. "Tactics like these wind up undermining the whole advocacy dynamic."