Organizational investments in complex information systems (CIS) have reached a record high. However, the underutilization of these expensive CIS prevents organizations from achieving the advertised return on investment. This study attempts to address this issue from the perspective of extended use and emergent use. Extended use concerns using more of the technology features, while emergent use concerns applying the technology in a novel manner to support task performance. To study uses that surpass routine use, a special focus is placed on the motivational factor that drives these behaviors. Drawing upon the insights from information system (IS) infusion, the IS continuance model, and the symbolic adoption theory, this paper proposes a research model for understanding extended and emergent use in mandatory organizational contexts. The model was examined in two large manufacturing firms that had implemented CIS for at least two years. The results suggest that perceived usefulness, satisfaction, and symbolic adoption influence extended use, and that perceived usefulness, symbolic adoption, and extended use affect emergent use. More importantly, the concept of symbolic adoption offers a theoretical explanation for extended and emergent use from the motivational point of view. Implications for theory and practice are also discussed.