Smart cards can be found in almost all mobile phones, in many credit and banking cards, and in public transportation access cards. Smart, stored cards, or other related cards especially play important role in the system of micro-payment. However, for many kinds of related cards, it's not convenient to customers or users. This paper attempts to develop a mechanism to solve the problem. That is, we design a mechanism that the customers can exchange mutually with reward points that can be redeemed for real goods and services. In addition, the paper provides the basis for valuing electronic payment in terms of game theories and derives the optimal fees for the electronic payment. It also provides micro-payment managers with an easy-to-understand framework to assist in evaluating and justifying micro-payment.