Fashion influencers’ credibility on Instagram: the stimulus–organism–response (SOR) perspective

Fashion brands' campaigns on social media typically rely on official brands' accounts and influencers' accounts. Drawing on S-O-R model, the current study examined how source credibility (expertise, trustworthiness, and similarity) and parasocial relationship influence marketing effectiveness of social media influencers. To test hypotheses, this study collected 232 samples and applied survey method to address the impact of marketing effectiveness on expertise, trustworthiness, and similarity of social media influencers. The findings indicated that influencers with high credibility were found to be positively related to advertising attitude and self-brand connection, which may be more effective in marketing effectiveness than those with low source credibility. Additionally, parasocial relationships were found to moderate the effect of influencers' credibility on self-brand connection, but not on advertising attitude. Overall, this research investigated the efficacy of fashion Instagram influencers in marketing by considering the factors of source credibility and parasocial relationship. Incorporating these dimensions can lead to more accurate predictions of consumer behavior and improved strategies for fashion brand management. The findings provide practical implications for fashion brands in selecting appropriate influencers and developing effective social media marketing strategies, particularly in understanding how influencer credibility affects consumer behavior.