This study addresses how customers develop loyalty toward focal stores within an online shopping mall, and how this construct affects behavioral mall loyalty in both the short- and long-term. We employ a type II Tobit model to dynamically capture the short- and long-term impacts of store loyalty on purchase incidence and purchase amount. We further embed this model within a model of store loyalty formation to elucidate its driving factors. Applying the models to purchase history data of new customers in an online shopping mall, we observe that store loyalty has an immediate negative effect on purchase incidence; however, given a purchase, this variable increases the purchase amount in the long-term. Additionally, the formation of store loyalty appears to be significantly affected by gender, age, cumulative purchase amount, cumulative purchase frequency, and time trend. We discuss the implications of these findings for mall owners in an effort to increase revenue contribution of their tenants.