The teacher in me loves commercials. They make wonderful teaching material, not just because they illustrate rhetorical topics like ethos and pathos, but because they require savvy viewers to think.
Thinking is a skill that takes practice and advertisements offer plenty of chances to flex your brain. Every commercial you watch on t.v. or hear on the radio is another chance to flex your critical thinking skills and analyze how you're being marketed to. Educated people should never be duped by the tactics advertisements use to try and make a sale.
The following video isn't one of the commercials I've used in my lessons in the past, but you can bet it will be making an appearance in the future. It explains what the terms you think you recognize in the dairy aisle of your grocery store really mean. Linguistically, I like this video because it points out the ambiguity of language and the power that words can have. Educationally, this video is a good endorsement of why critical thinking skills are important outside of the classroom.
For the squeamish among you, this video does not contain any graphic images; there is a shot of a chicken without a beak in the beginning, but it passes quickly and no animal is mutilated during the video. Yes, in addition to educating people about marketing terms, this video has an agenda. I have no problem with its promotion of local, independent farms (just be aware that were this video an essay, it would not only be categorized as "informative" but also "persuasive").