Studying the writing strategies used in advertisements helps students discover that rhetorical technique and patterns of development are not a system of arbitrary rules, but a means of achieving specific and real effects. By analyzing its purpose, audience, persona, and argumentative content, students learn how each element contributes to an ad's total impact. They can discuss the effectiveness of different types of evidence and the various modes used to develop advertising arguments. In addition to recognizing the use of analogy, comparison and contrast, and other modes, students can find examples of faulty argumentation in advertisements. They can develop a greater sensitivity to the importance of word choice after studying the "weasel words" and glittering generalities used to sell many products. Having familiarized themselves with ad techniques, students can use them to write essays on advertising. In an especially effective assignment, students design an ad for a nonexistent product and then write an essay analyzing what they did and why. Besides offering a stimulating way of teaching rhetorical strategies, this unit on advertising increases student sensitivity to the audience's needs, a quality necessary in any effective writing. (MM)