The fifth format is the "exemplary story." These ads weave a narrative that helps illustrate the product's benefits. In Gunn's words, the key is to create "a situation where you'd use [the product] and be very glad for it."

With only 30 seconds to spin a yarn, many story ads end up feeling hokey. (Sissy's school play is tonight, but there's a stain on her carrot costume. What will mom do?) But a well-done story spot can be a gripping little episode.

Consider this Volkswagen ad. It's shocking and violent, but at heart it's really just an exemplary story spot. Once upon a time, some people went for a ride in a Volkswagen, gabbed about trivial matters, got into a scary accident, and emerged unscathed—thanks to the VW's excellent safety features. The end.