Verbal self-reports of pain sensations are especially susceptible to expectancy effects: if I think I'm getting a painkiller, I might well report less pain than I actually feel.

I don't doubt that this is a "real" effect but we still have to distinguish pain vs. suffering, the objective and subjective components; as the saying goes "pain is inevitable, suffering is optional". So, I readily grant that some suffering is manipulable through expectancy effects. But there might exist better, more effective ways to alleviate suffering.

To me this still doesn't justify, e.g. selling sugar at a hundred times its market price.

As for "injection has a larger effect than pills", for instance, I doubt the strength of the data. The Wikipedia entry on placebo references a single 1961 article for this assertion, and the article would be ideal for this purpose since it focuses on an objective outcome measure (systolic and diastolic pressure) rather than subjective pain assessment.

But the Wikipedia commentary falls straight into a classic mistake of statistical inference: it confuses a difference of significance between two groups (the injection and oral placebo groups) with a significant difference. The oral placebo didn't show a statistically significant effect and the injection group did: this doesn't mean that there is a statistically significant difference between the two groups.

The citation for "acupuncture has a stronger effect than a pill" is to a Kaptchuk study that measured self-reported pain levels, so to me it's only saying "there is a stronger expectancy effect from having needles stuck into you than from taking a pill", which isn't earthshaking. Tellingly, the objective outcome measures (e.g. grip strength) showed no significant differences - my arm may feel better with needle treatment but it doesnt work better.

I'm not finding a citation for the bitter vs sweet thing in a quick Google search.

It's been claimed that color matters, but the one literature review I've looked at found these effects "inconsistent" across the studies examined. The studies were of poor quality in general and measured different things so a meta-analysis is not possible. Annoyingly the review reports things that strike me as irrelevant such as "the perceived action of different coloured drugs" which basically consists of asking people what they think a red drug will be most effective for. To me this sounded like a desperate bid to convince readers that "research contributing to a better understanding of the effect of the colour of drugs is warranted", the conclusion of the abstract. Sigh.