User interface design makes an important contribution to the effective presentation of online entertainment products. In this chapter, we examine two models in predicting user acceptance of online computer games. The first is the technology acceptance model (TAM) from the information systems field, while the second is a consumer behavior model based on marketing and advertising research. A field study was conducted to empirically test the two models. Results indicate that both models explain a significant amount of variance in our dependent variables: attitude toward the game and intention to return to the game, with TAM a more consistent predictor of both result variables. This study sheds light on research of Web-based product presentation in general and that of entertainment products such as online computer games in particular.