Your most unhappy customers are your greatest source of learning. Bill Gates
You can't just ask customers what they want and then try to give that to them. By the time you get it built, they'll want something new. Steve Jobs
The real and effectual discipline which is exercised over a workman is that of his customers. It is the fear of losing their employment which restrains his frauds and corrects his negligence. Adam Smith
The customers are known to the shopkeepers. Kashmir Proverb
Customers are jade; merchandise is grass. Chinese Proverb
When going to an eating house, go to one that is filled with customers. Chinese Proverb