I am very much not convinced of the interpretation of the placebo effect as "the fact that just thinking that you're getting some treatment of benefit can have actual benefits." The placebo (and corresponding nocebo) effect is completely intuitive when you think of it as a measurement artifact. It's strongest in self-reported outcomes, it goes away or is massively reduced the better your blinding - all exactly what you'd expect from a combination of confirmation bias and expectations (both on the part of the person receiving the treatment and doing the study).<p>Even to the extent that there are placebo effects in clearly quantifiable outcomes (e.g. blood pressure, etc) it's <i>still</i> way more plausible that these are due to nonspecific treatment effects (e.g. taking a pill every day for your blood pressure reminds you of your problem with blood pressure and so you take the stairs instead of the elevator or you don't have a second serving of steak) than that there's a way for your mind to just cause arbitrary positive or negative effects above and beyond your normal immune system - but only if it's tricked into it.
Extending this a bit further, I think this applies to things like cars or cosmetics or fashion or wine. Pretty much any consumer good actually.<p>I remember a study (might be from the Ariely book) where they took wine from the same bottle, put it into two decanters, and said one was way more expensive than the other. People were asked their impressions of the two wines. The more expensive wine received rave reviews while the supposedly cheaper one was marked only passable.<p>Interesting on one level, sad on another. And exploitable for profit, as some smart marketers have been doing for a while.
Speaking of expensive placebos, how is selling oscillococcinum legal? I can't imagine how many well-intended people mistakenly buy these sugar pills believing it is efficacious medicine.