The 1st goal of this study was to investigate how online communication is related to the closeness of existing friendships. Drawing from a sample of 794 preadolescents and adolescents, the authors found that online communication was positively related to the closeness of friendships. However, this effect held only for respondents who primarily communicated online with existing friends and not for those who mainly talked with strangers. The 2nd goal was to refine 2 opposing hypotheses, the rich-get-richer and the social compensation hypotheses. Consistent with the rich-get-richer hypothesis, socially anxious respondents communicated online less often than did nonsocially anxious respondents. However, socially anxious respondents perceived the Internet as more valuable for intimate self-disclosure than did nonsocially anxious respondents, and this perception in turn led to more online communication. This result is consistent with the social compensation hypothesis. Online communication and closeness to friends increased with age. There was a curvilinear relationship between age and perceived value of the Internet for intimate self-disclosure, such that 15-year-olds were at the epitome of online self-disclosure. Girls were closer to friends and more socially anxious than were boys.