Walter Ong & my Inquiry topic

When looking through and reading different essays in the Cross - Talk book, the only one that really seemed to have any relevance to my topic was "The Writer's Audience Is Always Fiction" by Walter Ong. The main point of this piece was that a writer needs to imagine their audience. I think this relates to advertising because when designing an ad, ad companies need to understand who their audience is so they can create the best ad for them.