The IS continuance model has been extensively applied in past studies for investigating continued information system (IS) usage behavior. The current study attempts to extend the post-adoption beliefs in the IS continuance model based on effort-accuracy model, by extending the application of IS continuance model beyond an instrumental focus. The extended IS continuance model, incorporating the post-adoption beliefs of perceived usefulness, perceived decision quality, and perceived decision effort, was empirically validated with data collected from an online survey of 626 existing users of online product recommendations (OPRs). The data analysis revealed that the extended IS continuance has good explanatory power (R2 = 62.1% of continued OPRs use intention, R2 = 53% of satisfaction, R2 = 50.5% of perceived usefulness, and R2 = 9% of perceived decision effort, and R2 = 72.3% of perceived decision quality), with all major paths supported except two. We also analysed the data on the original IS continuance model. The higher variances explained for the extended IS continuance model (D6% in continued OPRs use intention, D5.1% in customer satisfaction, and D3.2% in perceived usefulness). Hence, the extended IS continuance model can provide additional information that is relevant for understanding continued IS use. The significant effects of post-adoption perceived decision quality signify that the nature of the IS can be an important boundary condition in understanding the continued IS usage behavior. At a practical level, the extended IS continuance model presents IS product/service providers with deeper insights into how to address IS users’ satisfaction and continued patronage.