Modern drug companies have made big bucks capitalizing on the power and ubiquity of the placebo response. The best way to get great results with a pill is to treat people who don't really need it -- the highest placebo response rates occur in those who would get better naturally on their own. The really brilliant marketing trick was to persuade doctors to treat patients who weren't really sick, while at the same time convincing normal people that they were really sick. Expanding market share to include the worried well not only greatly enhanced the customer pool, but it also ensured the most satisfied of customers. Placebo responders often become long-term loyalists to medication use even when the medication is perfectly useless, both because they have no way of knowing it played no role in their getting better and because they are often untroubled by side effects -- a cunning combination that creates the dream customer base for drug companies and their shareholders.
Allen Frances, M.D, "Saving Normal," pg.99-100