Previous studies regarding the effects of interactivity on the web advertising are mixed. Many authors have proposed the positive effects of the interactivity whereas others underline its negative aspect in the online environment. The present study examines the product involvement and the motivation as moderators of the effectiveness of an interactive website under the light of the Elaboration Likelihood Model (ELM) theory. An experimental design was employed and the data, analyzed with SPSS (MANOVA and Regression Analysis), released a number of interesting findings. Overall, the most intriguing finding is that the direction of the interactivity effects can drastically change with certain product categories, which implies that increasing level of interactivity may not always yield positive communication outcomes. Therefore, web designers should take into account a number of factors that moderate the effectiveness of online advertising such as product involvement. What is more, the appropriate interactivity level should be selected based on the goals of the online advertising strategy.