We all understand the basic principles underpinning marketing activity: to identify unfulfilled needs and desires and boost demand for the solutions a product is offering. The mantra is always "sell more." De-marketing tries for the very opposite. Why would a company actively try to decrease demand?

There are many good reasons to do so: a firm cannot supply large enough quantities, or wants to limit supply to a region of narrow profit margin. Or, crucially, to discourage undesirable customers: those that could be bad for brand reputation, or in the case of the finance sector, high...