Every company needs to have the best customer service they possibly can, especially since it is generally less expensive to keep an existing customer than it is to attract a new customer. Here are five things which you can do to significantly improve the customer service you offer: 

1. Anticipate future customer needs
Customers who buy certain products or services may need other follow-on items or services to get the most out of their purchase. When you recognize this, you can make helpful suggestions to your customers so that they get the full value from what they are buying. Data mining (from your customer loyalty program, or other customer database) can help you determine what these needs may be.
2. Asking customers for in-depth feedback
Every customer has had the experience of being asked a stock customer service question: "How was everything today?" "Oh, it was fine." You will not get true insight into customer needs, opinions, and certainly will not be able to discover new opportunities to serve your customers better with these stock questions. Instead, you should seek to ask more in-depth questions, so you can get feedback which really matters, and which you can use to make a real difference.
3. Help your best customers meet each other
Your best customers may have solutions to each other's problems which you do not offer, or which you can not reasonably meet. Furthermore, your best customers can help each other by answering questions, sharing helpful tips about your products and services, and revealing surprising beneficial information which you might have been unable to share with them. Perhaps the best reason is that when customers realize that people like them choose your business, this creates a shared sense of identity which your competitors will have to work hard to imitate.
4. Systematically eliminate problems customers have brought up
Often, the problems customers have are ones which other customers also experience (but which they are too polite to mention). These problems can be insidious since your less vocal customers may not complain about them. However, if these less vocal customers feel dissatisfied enough, they may leave and never return, even if they can not explain why. The best customer service solution? Fix all the problems you can, when they first occur. It just costs too much to lose customers to problems that you already know about.
5. Understand more about your customers
The only way to develop meaningful product and service improvements (which your customers will pay money for) is to understand their needs, goals, and problems. You should strive to learn all you can about your customers, especially your best customers. They will be the source of your next great innovation, unless you intend to target a completely new market segment. Even if you are expanding to meet the needs of other customers, you should still seek to learn as much as you can about these prospective customers, so that they are likely to choose your business to meet their needs.

So, when you figure out what customers need next, ask them for deep feedback, help them meet others like them, remove reoccurring problems, and know more about your customers, it is possible to dramatically improve your customer service performance.