The audience is everything in a paper. Without and audience, how do you know who you are talking to? Understanding your audience can help your style of writing to better fit with the lever of understanding that the audience can commit. When people make an ad, they have to focus on what people would want to buy the product or else it would never sell. Understanding who you are writing for is absolutely the most important thing the writer needs to consider. This also help you understand HOW you are going to write. I would never use the same dialect I would use with my parents as I would my friends, they just would look at me funny. Audience is key to an understanding and appealing paper: it's everything that matters.