Appeal to authority is a fallacy of defective induction, where it is argued that a statement is correct because the statement is made by a person or source that is commonly regarded as authoritative. The most general structure of this argument is:
X says Y
X is authoritative
Y is true
The Mr. T add is almost an extreme example of appeal to authority, he is literally yelling at you to buy the product, the issue is that is he an inappropriate authority on the subject. And I think the answer is pretty clear; he’s not. But by using someone so very recognizable as Mr. T yet so different from the people you think of who would play World of Warcraft (lets face it, I think of fat white guys) that it really gives the sense the game is hip unique, and has aspects that surpass pre-conceived notions.
thumb|right|250px The Dr. Dre Dr. Pepper ad is an appropriate example of appeal to authority. Dre explains that because he is a Dr. (because of his music name) he should be trusted. "Trust me, I'm a Doctor."
The ad is also influential because its set in the part scene, with a famous rapper telling you that you should drink the product he's advertising. Who wouldn't want to?