The expectation-confirmation model (ECM) has often been applied to investigate the satisfaction with and continued use of information technology (IT) after its adoption. This theory, which is based in social psychology, has already proven to be useful in the evaluation of IT post-adoption behavior. However, this project identifies a few important omissions that, if modified, could improve the ECM’s theoretical validity and applicability. First, we argue that the ECM has important missing variables that affect user satisfaction and continuance. These variables include users’ cognitive consonance/dissonance, a psychological state that arises in response to the confirmation or disconfirmation of their expectations about the services received; individual influences that moderate this relationship; and social influences, a psychological variable that can help explain why dissatisfied users choose to stay and satisfied users choose to leave. The inclusion of these variables in the ECM could better explain the psychological evolution from expectation confirmation to continuance. Additionally, the ECM has been validated in many studies using data from continuers, but it has been insufficiently explored in the context of discontinuers. In reality, continuers and discontinuers behave differently, opting for various decision alternatives after their IT adoption. Thus, research efforts should extend the capacity of the ECM to accommodate and explain the post-adoption behavior of both continuers and discontinuers.