Certain children will have the attitude that they do not need to earn an incentive prize given for such things as learning memory verses or bringing a friend and will ask to have one anyway. If given, it no longer has the effect of an incentive (and it isn't fair to those who earned it.) You may, however, chose to find another way of awarding the child, such as asking the child to help straighten up chairs or distribute memory verse tokens or take-home papers.