If you're not earning the income you could be, or should be, that may have nothing to with the interior design services you offer. It may have everything to do with the fact that not enough people know about them.

Too many design professionals leave too much money on the table because they fail to inform clients about the full extent of their services. As a result, those designers end up settling for "one and done" projects, rather than for far more lucrative long-term relationships.

These "fee and flee" designers, who disappear shortly after they get paid instead of informing their clients of additional service options, do those clients and themselves a disservice.

Few people know all that you do, or can do. That's why the "services" list on your website and on your social media sites is so vital. Here's where you should ignore the "brevity is better" rule of online marketing and spare no detail about what you have to offer. Rather than simply referring to your "complete range" of design or decorating services, spell out those services.

Use your services page to account for all the options you offer — from project management to plumbing, from remodeling to redesign, from space planning to shopping. You may even want to include a list of all the product lines you offer.

Educating your customers about all of your design services is, in itself, good customer service. It provides them with the opportunity to do additional business with a design professional they know and trust. And it saves them the time, money and stress of having to seek out and select another vendor.

Then, too, promoting additional services to your current clients makes good business sense. Peter Drucker, the late management consultant, estimated that you have a seven times better chance of closing a deal with an existing client than with prospective one.

Studies show the long-term value of each client is more than 100 times the value of a single transaction. Not only do you make money in ongoing relationships, but you also save it. It costs five times as much to attract a new customer as it does to retain an existing one.

It's worthwhile to promote your entire array of services, even if you specialize in only one of them. You might introduce yourself, for example, as a kitchen and bath professional "who also offers residential remodeling services," or as a home stager "whose other services include color consultations and interior redesign."

The initial consultation provides you with an exceptional opportunity to discuss all of your capabilities. Ask the right questions — e.g., "How's the kitchen working for you?" — and you'll discover lots of challenges that prospects want to resolve.

Acknowledge their "pain," and present yourself as the caregiver who supplies the remedy. Inform them that you offer the services that can help them overcome their challenges.

Make 2017 the year you maximize every sale by informing clients about all you do. They'll appreciate it, and your profits will appreciate in the process.