>The question is will they reach for a coke or a pepsi? How about plain old cold water? Is a Cola much better at quenching thirst than plain cold water? EDIT

>The question is will they reach for a coke or a pepsi? How about plain old cold water? Is a Cola much better at quenching thirst than plain cold water? EDIT for clarity: The point is, the first question is not "Will they reach for a coke or pepsi", but "Will they reach for a bottle of cold water or a cola", then only the question of choosing between pepsi or coke comes. So you first need to convince people that you should drink a cola when you are thirsty. This is where the "evil" part comes from.