The thing you should know about subliminal advertising is … absolutely nothing. Why waste brain cells on something that doesn’t exist? And, unlike other silly sciences like, say, alchemy, nobody ever seriously thought it did exist.
Why do we all talk about it, then? Advertising.
The whole concept was a Hail Mary move by a struggling advertising company. This guy, James Vicary, needed a gimmick to compete, so he convinced a movie theater owner that he could improve his concession sales. He rethreaded the film to cut in a few frames here and there with the words “Eat Popcorn” and “Drink Coca-Cola.” Then, after the movie aired for a weekend, he ran to all the other movie joints in the area to brag that he’d increased sales of both popcorn and Coke with this little maneuver.
So did it work? No, not really. That particular weekend did see a slight increase in sales, though it quickly leveled off again and was more likely due to a change in the room temperature of the theater. They certainly never conducted any research on the subject.
Vicary himself admitted in later interviews that the whole thing was a hoax. There is even speculation that the whole thing never happened at all, as no theater ever admitted to working with Vicary on this.
So why on earth do we still talk about it?
A) We are such a paranoid society, constantly worried that someone will make us do something we don’t want to by getting inside our heads. It’s why shrinks make us uncomfortable and stage hypnotists have such clout.
B) Vicary wasn’t the last adman to need a hook. Though the FCC quickly banned subliminal advertising from television and movies (just in case it did work), it’s common practice in graphic design to insert or suggest things within graphics – to hide elements of one image within another. This is so prevalent in modern print advertising that a quick search will turn up thousands of websites “exposing” this, but they get the terminology wrong. Subtle or suggestive is not synonymous with subliminal advertising. Or, to put it even more simply: if you can see it, it’s not subliminal.
C) And finally, it’s exactly the sort of thing that Psychology Departments love to experiment with.*
Oodles of tests have been conducted over the last fifty years trying to link Subliminal Perception to actions. In other words, we know that if you flash images too quickly for the person to fully process what they’ve seen, they still may retain a vague sense of it. But it’s not strong enough to make a person do anything that they weren’t already planning to do. You just can’t manipulate people that easily.
But I’ll give Vicary credit — it would have been a billion dollar idea if it could have worked.