This study empirically examines the effectiveness of Token Promotional Pricing (TPP) within trial-based promotions and identifies the psychological mechanisms driving consumer responses. Utilizing a simulated English conversation course as the experimental stimulus, the research manipulated three price levels: free, token price, and regular price. Data were collected from a sample of 161 Korean college students. The results demonstrate that the token price condition elicited the most favorable responses regarding participation intention, attribution evaluation, and perceived fairness. Specifically, attribution evaluation emerged as a fundamental cognitive antecedent, significantly influencing fairness perceptions. Furthermore, both attribution evaluation and perceived fairness were found to significantly impact participation intention, with statistical evidence supporting a serial mediation effect. Moderation analysis further revealed that this indirect effect is amplified when participants attribute the promotional offer to external motives. Theoretically, this research extends the existing literature by uncovering a cognitive justification process that transcends traditional price-comparison models. Practically, the findings offer strategic insights for designing promotional pricing that fosters consumer trust and long-term engagement.