Given the context of the rising use and importance of social media for brand management, this research examines how brand attachment influences the effect of consumer-brand online interaction strategies on consumer attitude. In particular, using Goffman’s ‘face-work’ (1955) and social comparison theory (Schmitt 1988) as theoretical lenses, we investigate how brand flatteries towards consumers in social media impact the perception of brand humanization and the feeling of jealousy. According to face-work theory, individual interactions involve avoiding face-threatening acts and producing face-flattering acts in order to maintain one’s own face as well as the other participants’ (Brown and Levinson 1987; Kerbrat-Orecchioni 1997). Thus, appreciation and politeness should positively impact brand interaction perception in social media. However, the positive impact of brand flattery does not take into account the existing brand-consumer relationship and the consumer profile. Still, managers address various types of consumers on social media, for example those who have already experienced a relation with the brand and those who have not (i.e., consumers with high or low brand attachment). According to our conceptual development, we assume that brand comments flattering individuals (appreciation by the brand) have a higher positive effect on brand anthropomorphism when consumers have a low attachment to the brand than when they have a high attachment to it. Moreover, we assume that when a brand flatters others this generates jealousy for observing consumers. Based on two between-subject experiments, our results reveal the negative moderating effect of brand attachment, showing that the impact of brand appreciation on brand anthropomorphism is higher for consumers with low brand attachment versus those with high attachment. We also demonstrate that brand appreciation generates higher jealousy when addressed to others, compared to the self. On the one hand, this research contributes to the face-work, brand-consumer interaction and brand anthropomorphism literature. Indeed, our results depict brand attachment as a moderating variable of the effect of flattering expressions on anthropomorphism perceptions. Moreover, we demonstrate that brand appreciation has a detrimental effect on lurking consumers when the brand addresses other consumers. On the other hand, this research has managerial implications in the fields of branding and community management by proposing that managers could segment their online conversation platforms depending on the kind of brand relationships experienced by consumers. We also suggest that appreciation should be used with parsimony in order to avoid negative reactions from consumers who are not the targets of the brand’s appreciation.