Subliminal Messages are there to attract your attention. Possibly make you like it more.
There was a test on a documentary once, and some woman watched an advert. She said she hated (I think it was Shreddies) the cereal, but for some reason after watching the ad she loved them. Then some guys removed the subliminal back tracking with no words at all, and then she said the ad wasn't that special at all.
They're there to make the buyer like it more. I also watched a programme about magazine's corrupting people. And on a women's mag there as a huge pic of a guys c*ck in the background...which only the subconscious mind can see.
Also, you not telling me that Aladdin said "good teenagers take off your clothes" for no reason? Or Jessica (whatshername) flashing her you-know-what on the movie.
http://en.wikipedia.org/wiki/Subconscious
Look at that link ^ Will help you understand more
