From The Power of Influence I liked how they touched on ethos. Without credibility our arguments carry no weight. Establishing our credibility allows others to see us as honest and trustworthy. It is through this allows us to build up our persuasion tactics and convince a crowd that we are serious about our cause. Other factors correlate with this as well such as being personable.
Furthermore, it discusses how the essayist will indulge in their own ignorance. When a new question is asked the essayist will in fact begin to research the topic to become familiar with it. It goes further to discuss how the essayist will build boarders around the question and begin to paint on the canvince with answers that address the issue.
The Power of Influence goes on further but let me say this as a former target employee that sold an obscene amount of redcards. Ethos is necessary in any persuasion it allows us the opportunity to develop credibility and build rapport with the person we are talking to. If we do not take the time to research new questions that ruin our credibility than it will ruin our persuasion/ argument. This is the first building block to our tower of persuasion.