Here’s the thing about ‘Efficacy’. It doesn’t exist. It is an abstract concept, a placeholder, a shorthand, a broad clustering of ‘things that a product does’, a descriptor under whose vagueness all kinds of good things can hide. There is only one time in a Market Research presentation when ‘efficacy’ should be capitalised, and that is on the slide that shows “Efficacy: what doctors meant when they said they want more of it…”
Excellent writing.