Factors affecting consumer engagement on online social networks: self-congruity, brand attachment, and self-extension tendency

Purpose – This paper aims to examine a chain of relationships running from self-congruity with a brand – that can stem from the actual, ideal or social self – to brand attachment and from there to consumer engagement on social networking sites (SNS), specifically liking, sharing and commenting. It further advances self-extension tendency (SET) as a moderator affecting the self-congruity -> brand attachment link. 
Design/methodology/approach – Two studies were conducted to test four hypotheses. Study 1 (n = 282) engaged a self-administered survey with students at a large Australian university. Study 2 (n = 342) was conducted amongst the members of an Australian online panel and thus, enhances generalizability. 
Findings – Activated self-congruity orientations are brand-specific. Both studies reveal that two of the three self-congruity orientations affect brand attachment, which, in turn, influences consumers’ proclivity to like, share and comment on Facebook. Moreover, the self-congruity -> brand attachment relationship is moderated by SET. When SET is high, it strengthens the relationship between a self-congruity orientation and brand attachment. 
Research limitations/implications – Accepted methodological approaches were used to improve the veracity of the findings. Nevertheless, further research should consider a wider area of focal brands (e.g. store brands, mundane brands, luxury brands) and other SNS. 
Practical implications – SNS are widely acknowledged as a key marketing channel affecting both preand post-purchasing behaviours. Discussed here are means to trigger pro-brand advocacy behaviours. 
Originality/value – These findings extend existing theory in three ways as follows: they show social selfcongruity affects brand attachment in online contexts, brand attachment is a mediating variable affecting probrand social networking behaviours and SET moderates the self-congruity -> brand attachment relationship. SNS are widely acknowledged as a key marketing channel affecting both pre- and post-purchase behaviours; hence, these insights have theoretical and practical relevance.