The purpose of this research is to investigate the relationship between the presence of a virtual agent and web advertising effectiveness. For this, the researcher tested the effects of an anthropomorphic agent''s presence in making the web a more compelling experience for its users. He also tested the effects of an agent''s presence on consumer persuasion. The study is expected to contribute to theory regarding presence, persuasive effects of virtual experience, and nonverbal communication. It is also expected to practical implications for online advertiser, internet marketing manager and web site designer. Results of an experiment indicate that an anthropomorphic agent on the Web site can increase a sense of social presence and telepresence to influence some of the advertising effectiveness measures to be more favorable. Therefore, advertising practitioners should give more thoughts on various types of structural variables (e.g., modality) and content variables (e.g., agent''s voice and gesture) because creating a sense of presence is found to be effective to attract consumers and to establish more favorable relatioships with visitors.