You have given Placebo a negative connotations in your mind, to me a placebo can be a good or a bad thing depending on its use.

As K said PU can have a great effect on somebodies life if you can stick it out for a year and see through it or it can make you into a creep.

The same with other placebos - great if it helps you cures conditions or illnesses but bad if what you really need is medication and somebody is giving you homeopathy...

As for PU you would need to agree on what a successful PUA was which would be hard to pin down because different people want different things