This study incorporates unexpectedness, delight, and customer citizenship behaviors (CCB) into the cognitive, affective, and behavioral stages of traditional expectancy theories, which, in general, contain confirmation, satisfaction, and continuance intention in each stage, respectively. Data collected from 436 app users shows that, from the cognitive stage to the affective stage, satisfaction is affected more by confirmation, and delight is determined more by unexpectedness. In contrast, from the affective stage to the behavioral stage, satisfaction has a greater effect on continuance intention, and delight is more critical for customer citizenship behavior. This study contributes to traditional expectancy theories by highlighting the importance of unexpectedness in the forming of continuance intention, and by illustrating the relatively critical role that components of each stage play in subsequent stages. 
The effect of unexpected features on app users’ continuance intention