Purpose Self-promotion on social networking sites (SNSs) is a controversial issue as it has been attributed to various positive and negative consequences. To better understand the reasons for the mixed consequences and the nature of self-promotion on SNSs, the purpose of this paper is to theorize and empirically investigate the duality of SNS self-promotion and its underlying socio-psychological mechanisms. Design/methodology/approach By drawing on the motivational affordance lens and self-determination theory, this study develops a theoretical account of the duality of self-promotion on SNSs. The author places subjective vitality and SNS addiction as the positive and negative consequences of self-promotion. The model was tested using partial least squares technique with data collected from 289 Finnish Facebook users using a survey. Findings The results show that self-promotion contributes to both subjective vitality and to SNS addiction. Importantly, exhibitionism attenuates the effect of self-promotion on subjective vitality and amplifies the effect of self-promotion on SNS addiction. The feature-level analysis shows that status updates, adding photos, commenting in others' posts and profile completeness are the main determinants of self-promotion. Status updates, adding photos and check-ins, in turn, have high exhibitionistic appeal. Originality/value To date, the empirical attempts to investigate the duality of SNS use have been rare. In particular, prior research is largely silent in explaining what tilt the outcomes of self-promotion either toward positive or negative direction. The paper fills this theoretical and empirical gap and thus contributes to literature on dualities of SNS use.
