There's a reason why this sort of product will never go away, and it doesn't have to do with aural pleasure or smells or creating an environment where people can feel at ease. It has to do with the use of masked or hidden tones, broadcast outside of the range of human hearing, where measurement and recording devices can pick up those tones and match them to advertisers and consumers. Someday, when the statute of limitations runs out, I'll tell you all about it.
This is how a certain product works, and Muzak helps present this kind of thing in a palatable way. No wonder they make so much money piping in what is, essentially, just crap.