Although researchers have investigated the role of social media for luxury brands at an aggregate level, little is known about the success drivers of luxury brand communication in social media at a more granular level. This study aims to identify the characteristics of luxury brand communication content that trigger positive consumer affect, a key determinant of strong consumer-brand relationships. Specifically, we examine the impact of non-personal (quality, heritage, conspicuousness, uniqueness) and personal (hedonism, extended self) brand luxury dimensions on consumers’ affective responses to luxury brand posts. The results from a field study and an online experiment reveal that non-personal luxury dimensions evoke more positive affect than personal luxury dimensions, due to differences in their (perceived) vividness. Furthermore, the impact of certain brand luxury dimensions on consumer affect varies depending on consumers’ usage experience with a brand. Our findings help managers create social media content that contributes to strong consumer-brand relationships.