This article presents a theoretical rationale for using the Internet to conduct persuasive public health interventions. Through an examination of the conceptual bases of persuasion, it is posited that the World Wide Web and other Internet-based resources have many of the characteristics necessary for persuasive communication and may, in fact, constitute a hybrid channel that combines the positive attributes of interpersonal and mass communication. The notion that the Internet features many of the persuasive qualities of interpersonal communication makes it a prime candidate for the application of key behavioral science theories and principles to promote healthier behaviors. The broad reach that the Internet shares with many mass communication channels indicates an economy to Internet-based efforts to communicate with large audiences. It is concluded that if the Internet can be used for persuasive health communication and its reach continues to expand, it is time for public health professionals to explore the design and evaluation of Internet-based interventions directed at health behavior change.