The more congruent, the better? The role of recommendation content congruence on consumers' click-through intention in in-feed advertising

While format similarity is recognized as influential for in-feed ad performance, research on ad congruence has largely overlooked the role of congruence between ads and surrounding recommendation content. Drawing on the elaboration likelihood model, this study examines how this ad-recommendation content congruence influences consumer responses to social media in-feed ads. The results of four experiments show an inverted U-shaped relationship between ad congruence and consumers’ click-through intention, mediated by depth of information processing. Furthermore, the results demonstrate this effect is moderated by the in-feed channel (subscription vs. recommendation) and ad execution style (informational vs. narrative). Specifically, the subscription channel and informational ad execution amplify the positive effects of moderate congruence. These findings contribute theoretically by highlighting the potential downsides of excessive congruence and offer practical guidance for optimizing in-feed ad placement on social media platforms.