Every company tries to know who the best and idealistic customers are and how to identify them by use of the special methods. To solve this problem the diamond model of customer stratification, which is the conceptual model, is introduced in this research. We modified the customer stratification model developed by Narayanan et al. (2007). By use of this model we can find out the most profitable customers and then we can plan to improve the profitability of the rest customer groups.