It is widely assumed that advertising literacy makes children less susceptible to advertising effects. However, empirical research does not provide convincing evidence for this view. In this article, we explain why advertising literacy as it is currently defined (i.e., conceptual knowledge of advertising) is not effective in reducing children's advertising susceptibility. Specifically, based on recent insights on children's advertising processing, we argue that due to the affect-based nature of contemporary advertising, children primarily process advertising under conditions of low elaboration and, consequently, are unlikely to use their advertising knowledge as a critical defense. Moreover, literature on cognitive development suggests that children's ability to use advertising knowledge as a defense will be further limited by their immature executive functioning and emotion regulation abilities. Therefore, we argue that the current conceptualization of advertising literacy needs to be extended with two dimensions: advertising literacy performance, which takes into account the actual use of conceptual advertising knowledge, and attitudinal advertising literacy, which includes low-effort, attitudinal mechanisms that can function as a defense under conditions of low elaboration. We conclude our article with specific directions for future research and implications for the ongoing societal and political debate about children and advertising.