Show long-term clients how much you value their loyalty by creating an account management process that rewards them for keeping their business with you.
Most companies make the mistake of offering discounts and bonuses only to new customers. Instead of devising a scheme to reward new business, create a program that rewards loyalty. For example, perhaps your clients can receive a lower price after two years of continual service.
Take a look at your client acquisition plan and make sure it's not "sweeter" to become a new customer than it is to stay an existing customer. After all, long-term customers are far more profitable than new customers. In fact, some studies show that acquiring a new customer costs as much as 15 times more than selling more to existing customers.
Ask yourself this: Can you increase profits by spending some of the money you allocate for landing new customers towards keeping your existing clients?