AbstractIndividuals are increasingly sharing their consumption activities on social media platforms. However, the inferences people draw from consumption posts are understudied. Three studies showed that observers infer more self‐presentational motives and less self‐expressive motives when they see others post their luxury (vs. nonluxury) consumption on social media. The attributions of more self‐presentational motives and less self‐expressive motives lead observers to perceive the poster as inauthentic and undermine the observers' interpersonal interest in the poster. The negative effects of posting luxury consumption are attenuated when the post content emphasizes competencies (vs. wealth). This work contributes theoretically to the research on self, signaling, and social inferences. The current findings have practical implications for social media users and marketers of luxury products.