Why would anybody want to listen to what you have to say?

From here:
  1. because you help them
  2. because you entertain them
  3. because you make them hopeful and/or enthusiastic
  4. (maybe) because you say things they would like to say but cannot say

This is one of the many passages and charts I find in books and articles on a daily basis. They span many disciplines, including:

I occasionally add a personal note to them.

The whole collection is available here.