Beyond green claims: customer engagement activates green evangelism

Purpose Credible environmental claims frequently fail to convert into customer advocacy. This study aims to explain why. It positions customer engagement as the mechanism that activates green evangelism from perceived green reputation and perceived green credibility and openness to experience as a trait activated boundary condition on that activation. Design/methodology/approach A cross-sectional survey of 437 patrons of sustainability-positioned culinary establishments across five Indonesian metropolitan areas was analysed using covariance-based structural equation modelling in LISREL 9.30. Engagement was specified as a second-order construct with cognitive, emotional and behavioural facets. Mediation was tested with bias corrected bootstrapping, moderation with multi-group and latent-interaction estimation. Competing models, collinearity and equivalence diagnostics, common method tests and endogeneity checks were run. Findings Reputation and credibility predict evangelism only while engagement is left out of the model. Once engagement is specified, both direct paths fall to non-significance, and engagement remains a strong predictor, the signature of indirect-only mediation. Collinearity is negligible, so redundancy does not account for the pattern. Facet-level decomposition shows the transmission is carried mainly by emotional and behavioural engagement rather than by cognition. Openness strengthens both signal to engagement paths. Research limitations/implications Cross-sectional, single-country data on self-reported advocacy constrain causal and cross-cultural inference. Practical implications Marginal green marketing spend should move from claim broadcasting to co-creative touchpoints, tiered by customer openness. Originality/value The paper specifies an enactment threshold on green signalling models, supplies a mechanism-level account of the sustainability intention behaviour gap and joins trait activation to service-dominant logic in a two-stage activation-and-diffusion explanation of advocacy.