Virtual brand communities expose members to communication from the brand side and interaction with other members, but these sources may not relate to participation through the same psychological processes. Drawing on the stimulus organism response framework, social identity theory, and social cognitive theory, this study tested whether community identification and self-efficacy statistically accounted for indirect associations between parasocial interaction, interpersonal interaction, and customer value co-creation behavior. The hypotheses were examined in an unpublished cross-sectional survey of 240 adult users of virtual brand communities in China. An audit of the questionnaire and data codebook corrected a prior item-block parsing error and established the intended 30-item measurement structure. Internal consistency was acceptable for the five composites (Cronbach's alpha = 0.730–0.837; McDonald's omega = 0.744–0.838). A five-factor confirmatory model fit better than models combining the interaction constructs, combining the mediators, or placing all items on one factor, although its absolute fit and discriminant validity were only partly satisfactory (CFI = 0.870, TLI = 0.857, RMSEA = 0.064, SRMR = 0.056). Regression estimates used HC3 robust standard errors, and indirect associations used 5,000 percentile-bootstrap samples. Parasocial interaction uniquely predicted community identification and self-efficacy, and both variables were associated with customer value co-creation. The indirect associations of parasocial interaction through community identification ( B = 0.163, 95% CI [0.038, 0.303]) and self-efficacy ( B = 0.167, 95% CI [0.053, 0.281]) were statistically detectable. Interpersonal interaction retained a direct association with customer value co-creation but did not uniquely predict either proposed mediator when both interaction variables were included; its two specific indirect associations were not statistically detectable. Results were similar after excluding uniform responders and after adding demographic and community-use controls. The findings distinguish relational and capability-related correlates of parasocial interaction while showing that interpersonal interaction may share substantial variance with brand-side relational experience. Because the data are cross-sectional, same-source, and affected by incomplete discriminant validity, the indirect effects are interpreted as covariance patterns consistent with the proposed pathways rather than evidence of causal psychological mechanisms.

Promoting sustainable consumption requires communication strategies that make environmental benefits persuasive while recognizing consumers’ private economic motives. Drawing on the stimulus–organism–response framework, this study compares environmental versus economic advertising appeals for the same household product and tests whether consumer–nature empathy mediates their effect on purchase intention and whether environmental involvement conditions appeal effectiveness. A pretest (N = 60) validated two matched laundry-detergent advertisements. The main between-subjects experiment included 300 participants, with 150 assigned to each condition. Environmental appeals generated higher purchase intention than economic appeals (M = 4.33 vs. 3.35, d = 0.91). Consumer–nature empathy partially mediated this effect (indirect effect = 0.251, 95% bootstrap CI [0.139, 0.379]). Treating environmental involvement as a continuous variable revealed a significant appeal × involvement interaction (B = 0.524, 95% CI [0.371, 0.678]). Environmental involvement positively predicted purchase intention under environmental appeals but negatively predicted it under economic appeals. The findings show that sustainable advertising effectiveness depends on both affective resonance with nature and alignment between message framing and audience involvement. The study contributes to sustainable-consumption research by integrating message design, nature-focused empathy, and audience segmentation within a controlled experimental framework.