Warm Glow and Self-Expressiveness: Bridging Sustainable Service Design and Brand Advocacy in Saudi Arabia

This study aims to understand how sustainable services should be designed to foster favorable customer behaviors, which are critical for organizational success in the hospitality industry. Our study investigates the role of warm glow (WG) and self-expressiveness (SE), along with customer green identity (CGI), to develop a theoretical framework grounded primarily in Self-Congruity Theory and Signaling Theory. The survey was completed by 415 hotel guests, of whom 380 valid responses were retained after screening for completeness and response quality and subsequently used for analysis. Partial Least Squares Structural Equation Modeling (PLS-SEM), implemented using SmartPLS 4.0, was employed to analyze the data. The results indicate that sustainable service design (SSD) has a positive direct effect on SE and brand advocacy (BA) but does not have a significant direct effect on WG (H6 rejected). The CGI × SSD interaction on WG is positive but small and marginally significant (β = 0.043, p = 0.049; H13 supported), warranting cautious substantive interpretation. Both SE and WG positively influence BA, while the statistical indirect effect of SSD on BA through SE is significant but small. However, the hypothesized indirect paths via WG (SSD → WG → SE and SSD → WG → BA) were not supported. The findings suggest that identity-congruent sustainability cues and self-expressive motivations are associated with pro-environmental customer responses. Because the data are cross-sectional and self-reported, the indirect effects represent statistical mediation and do not establish temporal ordering or causal mechanisms.