From what I can tell, most companies focus their marketing efforts on bringing in new customers or clients. But I consider it far more important to retain that new business. And this requires a distinct set of communication skills and methods.

Indeed, keeping the lines of communication open with current customers and clients is the most important marketing skill of all. Current customers and clients must believe that they are your top priority, all of the time. This means you must provide exemplary service.

There are lots of ways you can engage with established customers or clients: face-to-face meetings, follow-up calls and emails, personal notes, formal letters, newsletters, mass mailings, opinion polls and surveys. You can also vary the content of each of these--offering news, educational information, status reports, error identification/correction, and general advice. My firm uses all of these.

Let's look closely at five of them.

1. Follow-up calls and emails. To maintain quality service, you must have feedback on how your customers/clients feel about the product or service you provide and the performance of your staff. You know your business best, so decide when the best time is to ask customers/clients about their satisfaction level. In some industries, immediate follow-up is best, while others might do best to wait 60 or 90 days, or even longer. In our view, we ask early and often.

2. Surveys and opinion polls. We conduct these often. The client responses help us learn where we can improve our client experience. Even just asking sends an important message: We care about what you think. Simple surveys can be implemented using such apps as keysurvey, questionpro, qualtrics, surveymonkey, polldaddy and zoomerang.

3. Error identification and correction. I say this tongue-in-cheek, but I love it when our staff makes a mistake. Why? Because it gives us the chance to show our clients how we respond. First, we strive to find errors before our clients do. That gives us the opportunity to contact the client and say, "We just found a mistake and wanted to let you know that we've fixed it. Everything is fine now. No worries." Clients love that fact that we're looking out for them, taking responsibility and being proactive, serving their best interests.

4. Formal letters. We send a formal letter to our clients a few times a year, or more when market events warrant. Look for reasons to communicate with customers/clients--perhaps simply to tell them about the latest news about your business, progress you've made, an honor you've won, or to review the past year and outline your plans for the next year. People want to feel that you're engaging with them.

5. Newsletters. My monthly 16-page newsletter provides a lot of personal finance news and advice that we couldn't provide as efficiently using other methods. Depending on your firm's scale and type of business, you might want to produce a newsletter too, or hire a firm to do it for you.

If your method of communication isn't working, try a different method. If you normally use email, try calling for a while.

Our view is simple: It's a lot harder to find a new client than keep a current one. So we lavish our attention on them. You should too.