Feedback is awesome.
Customer feedback is even awesomer.
Customer feedback helps improve your services, which in turn means more customers, and even more feedback, which you can use to improve your services, which in turn.... :)
Now, it’s a well known fact that most people don’t like leaving feedback. They may ask a couple of questions, but even if they do have feedback to give, they don’t always spell it out for you. So you have to learn to read between the lines.