Although the field of persuasive technologies has lately attracted a lot of attention, only recently the notion of ambient persuasive technologies was introduced. Ambient persuasive technologies can be integrated into every aspect of life, and as such have greater persuasive power than the traditional box like machines. This article discusses ambient persuasion and poses a model that structures the knowledge from social sciences on persuasion, attitude change, and behavior change. Using this model the challenges of ambient persuasive technologies to fulfill its persuasive promises are identified. From the ambient persuasion model it is clear that ambient persuasive technologies can go beyond traditional persuasive technologies by being context and situational aware, by interpreting individual differences between users, and by being a social actor in their own right. Keywords Persuasion Á Ambient intelligence Á Attitude change Á Behavioral change