Social media represent one of the fastest growing marketing channels in the world. Consequently, both researchers and practitioners are increasingly interested in the effects of social media marketing efforts on the likelihood of consumers to engage with and subsequently purchase from a brand. However, hitherto, little research has explored how social media users process the information they encounter on social media and how this information affects the nature and level of brain activity that occurs. In the proposed study, we will use functional neuroimaging (fMRI) tools to complement psychometric measures to specifically explore the neural activity that occurs in response to comments or electronic word-of-mouth; i.e., consumers’ responses to posts from brands on social media. The selection of comments focuses on two dimensions of theoretical interest, namely the nature of the comment—compliment versus complaint—as well as the nature of the brand the comment is targeting—low versus high involvement. The theoretical and practical significance of this study are discussed.