Social Media Advertising and Brand Loyalty in South Africa’s Retail Sector: The Moderating Role of Customer Engagement

Research Problem: Brand loyalty in South Africa’s retail sector is increasingly threatened by the fragmented attention and fluid preferences of digital consumers. Although social media advertising has become a dominant marketing tool, limited research has examined how advertising spend influences brand loyalty within this sector, particularly when moderated by customer engagement. Understanding these dynamics is crucial for retailers seeking to retain customers in a competitive digital landscape. Methods/Theory: Guided by Engagement Theory, this study adopts a quantitative research design to analyse the relationship between social media advertising spend, customer engagement, and brand loyalty. Data were obtained from 120 retail firms actively advertising on platforms such as Facebook, Instagram, and TikTok. Secondary data on advertising expenditure, platform engagement metrics, and customer loyalty indicators were analysed using hierarchical regression models, supported by diagnostic validity tests. Results: Findings show that social media advertising spend exerts a significant positive effect on brand loyalty. Customer engagement also demonstrates a strong positive influence on loyalty outcomes. Moreover, the moderating analysis reveals that customer engagement significantly strengthens the relationship between advertising spend and brand loyalty, indicating that advertising is more effective when audiences interact actively with brand content. Conclusion: Social media advertising contributes to enhanced brand loyalty in South Africa’s retail sector; however, its effectiveness is dependent on the level of customer engagement. Paid advertising alone cannot secure loyalty without meaningful user interaction. Key Contribution to Knowledge: This study enriches digital marketing scholarship by empirically demonstrating the moderating role of customer engagement in the advertising–loyalty relationship, offering evidence from a sub-Saharan African retail context where such insights remain limited. Recommendation: Retail firms should prioritise budget allocation for engagement-driven content, foster real-time brand–user interactions, and optimise advertising formats for interactivity. Further research should explore platform-specific engagement dynamics and cross-industry comparisons to deepen understanding of digital loyalty formation.