In the subject Thinking Skills, we are working with vested interest. A vested interest is when someone has something to gain from benefiting one side over the other, someone can present one-side arguments and reduce the credibility of a source. Our teacher showed us one of the episodes of the series "Mad Men". Where we can identify two different moments in which vested interest is used. One moment is when Peter comes out with an idea for the propaganda of the cigarettes company. he is telling one side of the story, the one which benefits the company. His idea is compareing the risk of dying in a car accident with the risk of dying with cigarettes. saying that life is dangerous, so if you are going to die anyway, why don't enjoy a cigarette. Peter is reducing importance to the fact that smoking leads you to death, which is what the company is trying to cover.
In another scene Don explains that there are six companies trying to sell the same product, but what he wants to highlight is that all the other companies sell cigarettes which are poisoned, but the company in which he is working, sells tobacco which is toasted. That is part of the production of every company's cigarettes, but, Don is telling just one side of the story, removing our sight from what really matters. Both of them are using vested interest to get benefit.
At the end just Don`s idea is accepted. because Peter`s idea accepts the fact that cigarettes are dangerous for our health. In conclusion, while one speaks about the risks, the other makes the audience focus on other things, so that we forget that tobacco is dangerous.