This work examines the determinants of the success of influencer marketing on the youth-focused TikTok, the fastest growing social network. It analyses the effects of influencers' account characteristics (originality, quality, quantity and humor) on their followers' hedonic experience and perceived opinion leadership, and how these impact on their intentions to follow influencers' accounts and advice. A survey of followers of a popular Spanish TikTok influencer showed that originality and opinion leadership play important roles and that, because TikTok is distinctive, humor increased the effectiveness of messages (through hedonic experience). Suggestions are made to advance the understanding of this novel phenomenon.