Head On/YMMV


 * Adaptation Displacement: Believe it or not, "apply directly to the forehead" was not the first slogan for HeadOn. The first included the slogan "Should I know about HeadOn?" But that just isn't nearly as memetic.
 * Ear Worm: How do you think they became memetic? Okay, having an annoying sound for their ads helps.
 * Memetic Mutation: How the ads became notorious.
 * so much, there have been various spoofs such as RockOn, a "Blooper" video featuring someone with no hand (and a floating head) amongst other things, Gmod videos advertising Headcrabs, and even Disaster Movie got in on the Head On spoof.
 * Most Annoying Sound