Abstract: In an experiment (N = 99) effects of subtle and prominent online advertising formats, respectively sponsored content and banners ads, on audience reactions toward the advertisement are tested. In addition, the role of several persuasion knowledge elements such as understanding of persuasive intent and ad skepticism, in processing online advertising formats is investigated. Results show that participants find the sponsored content more informative, more amusing, and less irritating than the banner ad. With respect to persuasion knowledge, recognition of the advertising format, understanding of persuasive intent, and ad skepticism are higher for banner ads than for sponsored content. Furthermore, ad skepticism seems to be strongly related to perceived advertising value. These new findings show that persuasion knowledge plays a role in the appreciation of subtle and prominent online advertising formats.