The impact of banner advertisement frequency on consumers' cognitive responses is investigated. A convenience sample of 200 respondents is recruited to surf the experimental Web sites. Applying logistic regression, the research identified a U-shaped cognitive response curve to consumers' responses to both static and pop-up banner advertisements, which is contrary to the traditional positive curve that initially increases with advertising frequency, reaches an optimal level and then increases at a decreasing rate. Theoretical and managerial implications are discussed.