Isn't that the same thing? What's the difference between wanting something and believing you want it? Doesn't one imply the other?
(Note: we're talking about wants here, not needs. It's quite possible to believe you need something and be mistaken. But wants are subjective beliefs, so almost by definition, wouldn't believing you want something mean that you do want it?)
Snake oil. False advertising. Advertising that stokes and intensifies desires far beyond the point at which they would exist sans advertising. Wanting a marshmallow now vs. two marshmallows later. Pepsi doing better on one-off taste tests, Coke doing better when consuming a 12-pack. Buying into the hype for something and deceiving yourself into believing it delivered. Misinterpretation. Projection. Insufficient information.
That is a good point. I've been in computers since '79 and never have I wanted (or witnessed someone wanting) an MS product. Rather, everybody felt the needed it because "it's compatible," "it's the way the industry is going", "it's the defacto standard"... Actual desire is nowhere to be found. The only time I can think of where Microsoft attempted to create actual desire recently was that god-awful Songsmith commercial.