Influencer marketing significantly impacts consumer behavior and decision-making. However, identifying the drivers of influencer marketing effectiveness and conditions that enhance their impact remains challenging. This meta-analysis, which synthesizes 1,531 effect sizes from 251 papers, assesses influencer marketing effectiveness by examining its antecedents, mediators, and moderators. Building on the persuasion knowledge model to develop and test a framework, we identify post, follower, and influencer characteristics as key antecedents impacting both non-transactional (i.e., attitude, behavioral engagement, and purchase intention) and transactional (i.e., purchase behavior and sales) marketing outcomes. For non-transactional outcomes, follower characteristics (social identity) have the strongest effects on consumer attitudes and behavioral engagement, while post characteristics (informational value and hedonic value) exert stronger effects on purchase intention. For transactional outcomes, influencer characteristics (influencer communication) have the strongest effects on purchase behavior. These antecedents also affect marketing outcomes indirectly through persuasion knowledge and source credibility. Moderation results indicate that direct and indirect effects of antecedents depend on social media types (i.e., nature of connection and usage) and product types (i.e., information availability and status-signaling capability). These results consolidate and advance the literature and offer insights into enhancing the effectiveness of influencer marketing.

影响者营销显着影响消费者行为和决策。然而，确定影响者营销效果的驱动因素和增强其影响力的条件仍然具有挑战性。这项荟萃分析综合了 1,531 篇论文中的 251 种效应大小，通过检查其前因、中介和调节因素来评估影响者营销的有效性。在说服知识模型的基础上开发和测试框架，我们将帖子、追随者和影响者特征确定为影响非交易（即态度、行为参与和购买意愿）和交易（即购买行为和销售）营销结果的关键前因。对于非交易结果，追随者特征（社会身份）对消费者态度和行为参与的影响最强，而帖子特征（信息价值和享乐价值）对购买意愿的影响更大。对于交易结果，影响者特征（影响者通信）对购买行为的影响最强。这些前因还通过说服知识和来源可信度间接影响营销结果。调节结果表明，前因的直接和间接影响取决于社交媒体类型（即连接和使用的性质）和产品类型（即信息可用性和状态信号能力）。这些结果巩固和推进了文献，并为提高影响者营销的有效性提供了见解。