Your customers are amazing.
Your customers are a pain in the butt.
Your customers are yours.
At the end of each day your business exists because you provide something amazing that your customers are willing to trade their hard earned cash for. When your customers feel you are less valuable then the cash they have to put out, they either go somewhere else or keep it stashed in their bank.
When was the last time you took the time to thank just one customer for being awesome? Actually telling them why they are so enjoyable to work with.
P.S. Hand written notes have an amazing effect on people. You show the person how much they matter when you take the time to think about them, write a note, and mail it.