In the competitive wireless telecommunications market, customer retention has become a priority to many carriers, as they face high customer acquisition cost and high churn rate. Prior literature has found that wireless customers often subscribe to inappropriate rate plans, and thus overpay for their services. A new database marketing strategy called ' Rate Plan Optimization ' has emerged, but literature in this area is still limited. This paper aims to strengthen our understanding of this strategy by analyzing the potential moderating effects of customer ' s frequency of handset change, frequency of rate plan change, customer age and contract status on the linkage between rate plan suitability and customer tenure. The data set covers 1249 wireless users in Canada. The hypotheses are tested by factorial Analysis of Variance (ANOVA). This paper argues that except customer ' s age, all other factors being analyzed have positive moderating effects on the linkage.