We collaborated with an influencer marketing agency to acquire a sample of 20,923 Instagram-sponsored posts across industries from 1,376 U.S. influencers. We measure engagement as the sum of likes and comments that a post receives. To measure language arousal, we combine a words-based lexicon (including terms like “hectic,” “amazing,” and “sensational”) with paralanguage (i.e., exclamation marks, capitalization, and emojis). We use 100,000 followers as the cutoff to classify micro versus macro influencers. To measure how informative the post goal is, we validate a dictionary with words like “explore,” “read,” and “watch.” Finally, we account for more than 100 controls, including details about the influencer, the text and images shared, and so forth. Combining the field data and controlled experiments result in some compelling results.
Consumers typically see micro influencers as regular people, so if they say something like “this shake is AMAZING!” consumers believe they really are excited about that shake and just want to share this discovery with their friends and followers. This belief in their sincerity increases consumers’ trust in micro influencers.
For micro influencers, a 10% increase in arousal is associated with a 5.4% increase in engagement, on average…If macro influencers increase arousal in their posts by 10%, it reduces consumer engagement by 8.4%, on average.
Our findings are not limited to Instagram. We offer evidence that language arousal also plays a role in TikTok, with relevant influences on its young target market. We gauge influencers’ vocal cues and the level of pitch in their voices as proxies for arousal. A higher pitched voice can signal greater arousal and, in line with our Instagram study, we determine that a higher pitch (i.e., higher arousal) voice exerts a negative effect for macro influencers.
For micro influencers, we find that a 10% increase in arousal is associated with a 5.4% increase in engagement, on average. Recommending a product by saying, “It’s superb” (vs. “great”), for example, would attract 49 additional likes or comments. However, our findings raise concerns for macro influencers. If macro influencers increase arousal in their posts by 10%, it reduces consumer engagement by 8.4%, on average.