As competition increases among ports, new marketing strategies and differentiated means in addition to the existing core services are needed to prevent existing container shipping companies from escaping and to attract new customers. The additional services and reward programs are investigated. How these variables affect relational commitment in terms of customer retention is examined. Customers of the container terminals are examined in terms of psychological behavior. This study presents the structural equation model that shows the connection among benefits, rewards, switching costs and relational commitment. The empirical analysis is done with the subject of the container terminal users and the implications are derived.