I ran through a few possibilities, including "Submit This Exact Comic" (which would have the first, second, and third panels fixed.) But that seemed a little too challenging, so I picked an idea derived from the movie "Crazy People":
The advertisers have gone nuts and concocted a completely honest campaign for a product or service. Examples:
"Quaker Oats: Do they taste good? Who knows, but the box is cute."
"Volvo: Boxy but good."
Pick a REAL brand-name and come up with your best honest ad strategy. Then, present this as:
(a) a commercial
(b) shocked executives previewing the campaign
(c) customers reacting to the ad copy
Incompetent advertising campaigns ("Nutrific candy bars are nut-very good!") aren't the objective. The theme is *honesty*. Since this is a paid advertisement, it should at some point stress a legitimately positive characteristic of the product...even if admitting to some weaknesses.
If you want to do a series, then do one strip for each of (a) (b) and (c), but no more than that for any single product. Multiple submissions encouraged (the-more-the-merrier). I'll judge when people have gotten obviously bored of entering, which seems to be inside of a week.