This study draws upon the service literature and operationalizes the investment model in the services domain to examine factors that contribute to customers’ desire to maintain service relationships with firms (i.e., retail banks) in an emerging economy in sub-Saharan Africa: Ghana. We empirically test the explanatory power and robustness of the investment model using 218 customers of various banking institutions in Ghana. Results from partial least squares—structural equation modeling (PLS-SEM)—reveal that (1) service quality is positively associated with customer satisfaction, investment size, and customer commitment; and (2) while customer satisfaction is positively associated with customer commitment, both investment size and quality of attractive alternatives are not associated with customer commitment. Interestingly, we found investment size to have a positive association with customer commitment only when fully mediated by customer satisfaction. Our model reveals that service quality and customer satisfaction predict 79.3% of the variation in customer commitment toward maintaining a service relationship with their retail banks. Discussion and managerial implications conclude the article.