The Snickers Trick

before someone gets up from their desk and walks down the hall, Mars is able to sell that person the idea of a 50cent Snickers. While this is not completely realistic - many times that snickers slot will be empty - it's enough to convince someone to get out of their chair, walk down the hall and 'check' the machine. At the machine, they've not only decided that they probably want something, they've begun to exert effort to achieve their goal. Upon finding the machine out of snickers, they either have to walk back disappointed (and now maybe slightly hungry, by suggestion) or they can get some other similarly priced snack to fulfill the need they created for themselves.

If, instead, at the beginning of the decision tree it was a 75cent guaranteed snickers bar then it would be a simple, rational decision - do i want to pay 75cents for this? The argument the marketing department makes is that there are are fewer people who rationally want that 75cent snickers bar vs. the people who can be sold on the dream of a 50cent snickers bar (that strangely looks and tastes more like a high-margin cookie).