Here's a 2009 article by Steven Pressfield in which he recalls how his days in advertising taught him a very important writing lesson:
Let me repeat that. Nobody–not even your dog or your mother–has the slightest interest in your commercial for Rice Krispies or Delco batteries or Preparation H. Nor does anybody care about your one-act play, your Facebook page or your new sesame chicken joint at Canal and Tchopotoulis.
It isn’t that people are mean or cruel. They’re just busy.