Abstract: As an essential tool for corporate brand marketing, social media influencer marketing brings significant traffic to brand com-munication. Based on the Elaboration Likelihood Model and the Persuasion Knowledge Model, this study utilizes real data from social media platforms to investigate the impact of four core factors of influencer-generated content on consumer engagement behavior. The re-sults reveal that the format of influencer-generated content, contents' hedonic value, campaign incentives, and campaign intent all have significant direct effects on consumer engagement behavior. Specifically, influencer-generated content presented in video format, with high hedonic value, campaign incentives, or brand-promoting intention, is more likely to elicit consumers' likes, comments, and sha-ring behavior. These effects are further moderated by campaign intent. Specifically, posts using videos (vs. text-image) and campaign in-centives (vs. no incentives) are more effective in generating comments and sharing behavior when the intent is to promote brand, where-as posts high in hedonic value (vs. low hedonic value) are more effective in generating comments when the intent is to increase trials.

Key words: influencer marketing, consumer engagement, influencer-generated content, campaign intent