This A new study suggests that the placebo effect can be invoked by advertisements.

As with all kinds of placebo effects, the placebo effect plays an important role in advertising especially during drug trials. The strongest factor behind the placebo’s in advertising is that it can influence the actual effectiveness of a product.

The expectations play an important role in the placebo effect; companies use the placebo effect in advertising to influence customer buying behavior.  For instance, a placebo effect on price, you’ve probably had discovered that many companies sell items at $99.99 instead of $100.00 or at “25 percent off the retail price.

From a scientific standpoint, it’s a positive response which does not derive from the actual ingredients but from the patient’s perception and expectations. These expectations can lead to inappropriate and excessive prescribing. Just as placebo (Latin word) means, “I shall please”

http://io9.com/bizarre-study-shows-that-advertising-improves-effective-992610371