Assuming you’re not in the business of selling something and then disappearing from the scene, it’s easy to identify your best prospects. They’re already your clients. Yes, your clients are your best prospects.

A relationship, even if fleeting, has already been established. And because you know something about your clients and their preferences and needs, closing business with them–instead of with people with whom you have no relationship–should be faster and easier. In other words, it’s easier to sell them on your products and ideas. Plus they’re more receptive hearing from you because of the rapport you’ve already built with them.

So, if your clients are your best prospects, treat them as such. Communicate with them. Often.

If you’re in a service business, place a phone call to your contacts, even when there’s no business to discuss. Notice I said a phone call and not an email. Ask how they’re doing. Ask if there’s anything you might do to assist them. And, speak with feeling, not as if you’re reading from a script. This tells your client that you see him as a human being, not as a walking paycheck. After all, your clients should be your closest allies–and your best references.

If it’s more appropriate, send your client a quick handwritten note. Be certain to differentiate this from what you’d send to a prospect with whom you have no prior relationship.

The important thing is to keep the lines of communication open.

Assuming it’s possible to have a more personal relationship, attempt to befriend your client contact. Try to remember birthdays, spouses’ and children’s names, and where they go on vacation; this will show you’re interested in them as a person and not as "the client." By building a friendship with your contact, they can be your ally if and when any conflicts arise. They can also do you the favor of telling others about your company’s products and services.

So, be a prospector, and go mine your client list. You’ll find plenty of gold right under your nose.