This study investigated Internet use among Taiwanese adults by using data from the National Communication Database. Employing a theoretical framework of problematic Internet use and media habits, social augmentation, and social displacement hypotheses, the author examined the relationship between individual differences, habits, and online activities, and their impact on offline face-to-face interaction. Results from structural equation models and bootstrapped mediational analyses indicated that a) strong preferences for online interaction, b) using the Internet when feeling lonely and, c) using the Internet habitually are critical factors that predict subsequent online activities. Among these factors, habitual Internet use exerted the strongest predictive power. Among online activities, the frequency of social network site use positively predicted the frequency of face-to-face personal interaction. By contrast, the frequency of online game play did not increase offline social interaction and elicited complaints from family and friends.