Facebook provides a way of connecting with friends online that increases the effectiveness of Internet advertising. This study investigates what factors influence the impact of consumers sharing advertisement (peer-to-peer) on communication effectiveness. The conceptual framework relies on social capital and communication theory, including tie strength, type of message, and advertising literacy. To test the research hypotheses, the study carries out two experiments involving 346 participants. The results show that interactive advertising gains greater consumer attitude toward the ad and higher message-sharing intention than non-interactive advertising does. The social tie is an important factor in moderating the effects of the message format and advertising literacy on communication effectiveness. This research advances the social capital and communication literature by explaining the effectiveness of consumers sharing advertising based on Internet-mediated communication. Research findings provide managerial implication for companies to better plan online marketing strategies in this social-networking era.