Are Readers Customers?

Paul Carr recently wrote a post at PandoDaily that many call "inside baseball" or "navel gazing." Some commenters said that those sort of posts aren't what they want to read.

While I don't care either way for "inside baseball" posts from PandoDaily, I suggested that the site listen to it's customers. Carr and Lacey both responded that they don't have customers, they have readers. Implying that they don't need to listen to them.

So, are readers of any media customers? Why or why not? I am open to being wrong, so tell me if I am.