It makes you buy awesome magical stuff that's actually crap.
Every commercial has to have something in it to make you buy it. The problem is that most companies stretch the truth so much that it ends up in dissipointment and potential violence. Have you seen an axe commercial lately? What do you see? Titties titties titties. Consider tag body spray's starting commercials, the guy merely picked the can up and was almost immediatly surrounded in a mountain of joy mountains and love caves. As for other kinds of overhype, look at halo 2's e3 gameplay video. In that video we were promised an excellent mission in a metropolis, shooting the shit out of aliens with a gauss cannon mounted warthog. Now, one would assume that we'd fighting on earth against the covenant hordes, right? Wrong. After about two missions you end up on a frigate and get warped to... (drum rolll) another halo ring! Oh, but wait! Before that, you get to be an elite! Yep, now you can be one of those nasty insect-human hybrids, and you're on the covenant side this time! Let's also look at grand theft auto 4. When you saw the trailer, what did you expect? Crazy shootouts, nutty car chases, and lots of guns. What did we get, you ask? About two sets of guns that all have about the same effect, knocking a person back a bit and then having to shoot them again, unless it was a headshot or an up close shotgun round. Yeah, it's got shootouts. However, you have to drive for up to 5 minutes to get to them but, oh what's this? You were killed? Well, enjoy driving for another 5 minutes again! It's like waiting for a plane to take off, getting to the runway, then having the plane go back to the gate and your flight delayed, but you also have to go through security again, and you also had to buy the plane ticket and wait in the boarding area again. Oh, but wait! You have these great activities, right? Again, wrong. You can go bowling, play darts, or play pool. You could pretty much get in your real car and go do all of those with your real friends. Look at movie posters. They promise action, boobs, explosions, and even giant rampaging monsters. Yet you go and all it is is a big chick flick without boobs or explosions, which dissappoints the boob and explosion lover in us all.