You need to establish a relationship with the people you are serving, and ask them how you are doing often.
Of course, this means you might not like what they have to say, your customer satisfaction score might be low, you will have to work harder, and perhaps eventually you will have to change quite a lot of your product or service, or even get out of business.
But it’s not you asking that makes these things true.
Things are what they are, and even when we refrain from finding out – because we don’t want to know we are not liked, or find out our hard work is not hard enough, or realize we won’t get that bonus or promotion -, they will continue on their course with no regard for our preoccupation.
At least, with knowledge, we might be able to adjust just in time.