What is the purpose of the audience in storytelling?

When writing or telling a story you have to consider your audience as you want to give them what they want. If you give them something other than what they want then you will lose them. Since you want to engross your audience you should consider them in writing your story.

There was an episode of 'Cheers' where Frasier Cranes makes a bet with the other regulars of the bar that his narration of 'A Tale of Two Cities' will intrigue them. When it doesn't he alters the book's contents and his delivery to something that captures their interests.