I think it's the same situation as so called "audiophiles" who spend large amounts of money on gold cables and ultra expensive headphones. They may or may not be able to tell the difference but the knowledge that their 10000USD headphones produce a slightly large range of sound than the 100USD pair makes them believe that the more expensive headphones are worth it. In the same way you could probably sell some sort of... DVD re...bluer? or something and make a mint even if no one could tell the difference.

I'm not sure it would work if no one could tell the difference, and I'll cite your example of the audiophiles.

Many people are overpaying for sound equipment that would sound no different to them than stuff half the price, but the fact that there are people that can tell the difference, who talk about that difference constantly, keeps the deluded part of the market in the dark. These people will never do some sort of double-blind test to identify whether or not they can tell the difference, but since there were originally people who could recognize it, others started to follow blindly. There has to be some starting off point before the masses buy into the hype.