You are spot that perception drives reality. But I will disagree with the statement that marketing believes in perception. I have met many marketing people who believe that if they can cram as many words onto an ad, or a powerpoint presentation, or if they can just talk about one more feature or function, then the product will sell itself.

I have seen rooms with floor to ceiling stacks of unused brochures created by marketing departments that believed that more things on the technical merits of the product is better.

It is the mistaken belief that it is a argument of points and scores that will win the customer, forgetting to address the perception held in the customer's mind.

Teaching a marketing person to understand the power of perception is extremely hard to do. You point out one of the main reasons, management doesn't believe in it. Few marketing people are willing to stand up to management and defend the belief of perception. Instead the produce reams of unused reality flyers, brochures, and white papers.

Believing in the power of perception and acting on that faith takes a tremendous amount of courage on the part of a marketing person. Learning to measure the effectiveness of the perception can successfully convert a skeptical management team because the data becomes their new reality.

I agree with U that the only reality is the perception.
I also note that all the examples u illustrated are related to brand extensions... maybe this buzz practice makes CEOs blinds...
I realize that expecially when there is the brand repositioning (as u illustrated in the book 'The new positioning') the risk to force percepitions is as high as with brand extenions... isn't it? When does the reposition work good?