This is the subject of one of my rants. My theory is that the very word customers acts as a cloak to hide the true meaning and significance of these people form us. It is a collective generalisation. It conveys absolutely nothing about the people concerned. On the other hand, if we use the real words to describe them specifically, we will find that we already know a great deal about them. We understand fundamentally what they want from us. We may still need to have conversations with them to get at, for example, relative priorities, but this is fine-tuning our service rather than addressing the basics.
Have a look at my Customers or Vegetables rant. How might treating our customers more like vegetables help us to do a better job of delivering good products and services to them?