Social media influencers rely on emotional connection to maintain and grow their followings and have value for brands. To date, however, no research has quantitatively examined the impact of emotion in the facial expressions and caption text that influencers use in their video posts on consumer engagement through likes, comments, and views of posts. Grounded in consumer brand engagement, psychological sense of community, and the behavior ecology view of facial displays, this study uses social media analytics, facial expression analysis, and computational linguistic analysis to assess the emotional substance of 402 video posts by prominent micro-, macro-, and mega-influencer mothers, known as InstaMoms, as exemplars of Instagram influencers. The study identifies that the amount of emotion used and specific discrete emotions have a meaningful influence on engagement, and both follower count and presence of branding saliently contribute to a more robust understanding of the relationship. Theoretical and practical implications are identified and discussed.