The shift in the accessibility of positive and negative information about consumer products on the Internet calls for a revisiting of persuasion effects. A counterintuitive effect, called the sleeper effect, predicts that attitudes toward a persuasive message have the potential to increase in favorableness despite the presence of information discounting the message. An experimental study was conducted to support the existence of the sleeper effect, demonstrate its renewed relevance in the contemporary advertising environment, and provide a foundation for further sleeper effect studies