How about this one, for each person who orders something: sort them into 2 categories.
Category A: Those customers who have their payment method in hand before they are told the price of their purchase.
Category B: Those customers who do not have their payment method in hand before they are told the price of the purchase.
Also deiced ahead of time how you will classify all the possible "gray areas" you can think of. Perhaps it would be good to go to a totally different kind of business and see what possible gray areas you will have to deal with ahead of time so you can make a comprehensive list. For example:
Woman fumbles through her purse while placing order but fails to actual retrieve cash (or you can't tell if she has it in hand because her hand is in her purse) before the total is told to her. Does this go into category A or B?
This post was edited by Azrad on Sep 30 2013 01:17pm