Don't take your existing customers for granted, or your existing customers may become someone else's new customers. If you don't treat them well, you can bet someone else will. Think of your current customers as if they were still unsold potential buyers. They deserve just as much attention as new customers. Simple things like returning their phone calls and staying in contact after a sales will improve your chances of keeping your customers from deserting you.
An example of treating your current customers royally can be found with one company that does tree and shrub trimming. It not only reminds each customer early in the spring to schedule trimming before the crunch starts, but it also leaves a small potted seedling for each customer to either plant in his or her own yard or share with someone in the community that might need help with landscaping.
Excerpted from 303 Marketing Tips: Guaranteed To Boost Your Business