“The Engineering of Consent” is an essay by Edward Bernays first published in 1947. He defines “engineering consent” as the art of manipulation of people.
It maintained that entire populations, which were undisciplined or lacking in intellectual or definite moral principles, were vulnerable to the unconscious and undue influence so as make them want things that they do not need. This was achieved by linking those products and ideas to their unconscious desires. Ernest Dichter, who is widely considered to be the “father of motivational research,” referred to this as “the secret-self of the American consumer.”
In other words Consumer Psychologists have already made the choice for us before we buy a certain product. This is achieved by manipulating desires on an unconscious level.
The central idea behind the engineering of consent is that the public or people should not be aware of the manipulation taking place.

http://www.youtube.com/watch?v=UcYBSXgtmKQ

The embedded video is part of the BBC series The Century of the self. The program explores how those in power in post-war America used Freud’s ideas about the unconscious mind to try and control the masses. Politicians and planners came to believe Freud’s underlying premise – that deep within all human beings were dangerous and irrational desires and fears. They were convinced that it was the unleashing of these instincts that had led to the barbarism of Nazi Germany. To stop it ever happening again they set out to find ways to control this hidden enemy within the human mind.