Mum's not the word. (Customer Service)
As a business, your main purpose is essentially to provide excellent customer service. Because you have a product (or service) you intend to sell, you need to provide a top-notch customer experience. In our world of technology, that means everything from the resources you provide online (do you respond to customers in a timely manner when they Tweet about your company...good or bad?) to the young clerk you hire on location. If you own a restaurant where the food is delicious but the service is lacking, which will your customers be talking about when they leave? The customers' experience can bring your company up from a '9' to a perfect '10.' In the long run, you are really developing relationships with your customers which equals repeat business.
Finally, while superb customer service may begin with you--the owner/manager--employees must be trained on how to continue to provide that same superb service. Maybe you have a cashier who doesn't realize she isn't smiling; point it out to her. But do it with respect. Because if she starts to smile (thus welcoming in more customers) business will increase which is good for her, right? Because she gets to keep a job. See? It all comes back around, full circle. A happy boss makes for happy employees which transfer to happy customers. Remember: word of mouth spreads quickly these days, so make sure the word is a good one!