What is subliminal advertising?

It is something very different in advertising than in the research laboratory. In advertising, it originally meant triggering a pleasant thought or association with an ad so the consumer would buy the product.

One study involved Chivas Regal and Marlboro. An ad-photo of Chivas Regal scotch whiskey was manipulated to include a "subliminal" naked woman image. The ad with the image got higher ratings for credibility, attractiveness, sensuality, and the likelihood the viewers might buy the product than the ad without the women image. A similar study with a male sexual image in a Marlboro ad did not score higher ratings, however.

Subliminal advertising has a more subtle side today. One form it has taken is "cinematic product placement" and "plugging" in motion pictures. Movies advertise products "subliminally" by prominently placing them on the screen or by mentioning specific brand names in the dialog. For this placement and plugging, the movie producers receive large sponsorship fees to help finance making the film.

I heard about a movie theater that flashed messages on the screen to get people to buy popcorn. Did it work?

James M. Vicary, a motivational researcher and amateur psychologist serving as Vice President of the Subliminal Projection Company, supposedly tried this.

On September 12, 1957, Vicary held a press conference to announce a six week ad campaign at a New Jersey movie theater to sell more popcorn and cokes. Using special equipment, his company flashed messages on the movie screen for 1/3,000 second saying "Hungry? Eat popcorn," and "Drink Coca-Cola." Vicary announced sales rose dramatically, but he never produced sales figures to prove his claims. Evidently, the entire thing was a sales gimmick to promote the Subliminal Projection Company.

Vicary coined the term "subliminal advertising" to describe this form of advertising.