Know your customer. Knowing your customer is one of the few keys to success as an entrepreneur. Know those you serve better than anyone else, and you’ll be able to deliver the solutions they need.
Also, learn from complaints. Your most unhappy customers are your greatest source of learning. In other words, you learn the most from your most dissatisfied customers. Let unhappy customers teach you where the holes in your service are.
Finally, ask for customers’ input. Assuming what customers want or need will never lead to success. You must ask them directly, and then carefully listen to what they say.