To those five giant industries that exist by selling mood-altering substances – alcohol, coffee, tea, tobacco and entertainment – should we add the placebo industry? After all, it’s not just the purchase of cosmetics that can be explained in this way – I would contend that a large proportion of consumerism is designed to achieve the same thing. In fact, much luxury goods expenditure can only be explained in this way – either people are seeking to impress each other, or they are seeking to impress themselves.fn1 Is almost everything a mood-altering substance?