The Best Influencer Post Depends on How Many Followers the Influencer Has

Brands spend heavily on influencers, but not every sponsored post earns the likes and comments that justify the fee. A study in the Journal of Interactive Marketing finds that two things shape engagement. One is the personality conveyed by an influencer’s words. The other is the content choices in the post. It also finds that the right recipe depends on how large the influencer’s following is.

Holly A. Syrdal, Associate Professor of Marketing in the Department of Marketing at Texas State University’s McCoy College of Business, is a co-author. Her collaborators are Susan Myers of the University of Central Arkansas, Sandipan Sen of Southeast Missouri State University, Parker J. Woodroof of the University of Alabama at Birmingham, and Marla Royne Stafford of the University of Nevada, Las Vegas.

The study

The research rests on two ideas. Parasocial theory describes the one-sided bond followers feel with a media figure they have never met. Signaling theory holds that the cues a sender puts out tell receivers something about the sender. Combining the two, the authors argue that a sponsored post sends two kinds of signals. Relationship-building signals strengthen the parasocial bond. Promotion-focused signals push the product. The two are expected to affect engagement differently.

To test this, the team used text-mining techniques to build a data set of 961 sponsored posts from 71 influencers. Each post was scored for linguistic personality, meaning the personality traits implied by word choice. The traits follow the familiar five-factor model: agreeableness, conscientiousness, extroversion, openness, and emotional stability. The team also coded content characteristics. These include whether the influencer or the product appears in the photo, and how many hashtags and emojis the text contains. Follower size was tested as a moderator, a variable that changes the strength of the other effects.

What the researchers found

Several factors mattered on their own. Agreeable language, which reads as warm and cooperative, raised engagement. A photo of the product lowered it. Heavy hashtag use lowered it as well. Emoji use and whether the influencer appears in the photo also played a role.

Follower size then reshaped many of these effects. Influencers with large audiences did better with conscientious language, which reads as careful and organized. They also gained from fewer hashtags and from appearing in the photo. Influencers with smaller audiences did better with language that reads as extroverted, agreeable, open, and emotionally stable.

The pattern is consistent with the signaling framework. Posts that come across as promotional, such as a product shot stacked with hashtags, pull down engagement. Posts that come across as personal and relational lift it. And what counts as the most effective personal signal depends on the scale of the relationship the influencer already has.

What it means for marketers and influencers

For brand managers, the results argue against a one-size brief. A mega-influencer and a micro-influencer should not be handed the same content guidelines. The larger account benefits from a measured, dependable voice and its own presence in the image. The smaller account benefits from an outgoing, upbeat voice.

For influencers, the findings offer a checklist. Keep the tone warm. Be careful with product-only photos. Use hashtags sparingly. And consider how large the audience is before choosing a voice.

For both, the study suggests that engagement rewards relationship signals over sales signals. The sponsored post that feels like a conversation tends to outperform the one that feels like an ad.

This summary is based on the paper’s abstract. The full article reports the data, methods, and detailed results.

What it means for managers

• Warm, agreeable language draws engagement. Posts that read as cooperative and friendly performed better.
• Go easy on product shots and hashtags. Photos that showed the product and posts loaded with hashtags reduced engagement.
• Match the tactic to audience size. Large influencers gain from conscientious language, fewer hashtags, and appearing in the photo. Small influencers gain from extroverted, agreeable, open, and emotionally stable language.

Myers, S., Sen, S., Syrdal, H. A., Woodroof, P. J., & Stafford, M. R. (2025). Signals for success: The intersection of influencer linguistic personality, content, and follower size. Journal of Interactive Marketing, 60(4), 436-451. 10.1177/10949968251317204