What Makes Influencer Marketing Work?

ContentPan, M.; Blut, M.; Ghiassaleh, A.; Lee, Z. W. Y. · 2025Journal of the Academy of Marketing Science
Topicsinfluencer marketing·social media·meta-analysis·persuasion knowledge·source credibility·purchase behavior·sponsorship disclosure

You are approving next quarter's influencer budget, and the easy way to justify it is reach: rank the accounts by follower count and fund the biggest. That is the number everyone can see and defend. Before you sign, ask what is actually associated with what moves your audience. The evidence favors a trusted creator, a genuine brand fit, and content people find useful and enjoyable, with raw follower count the weakest predictor of results.

Follower count is the wrong primary thing to buy in influencer marketing.

Marketers routinely equate reach with results, so budgets chase the biggest accounts. Pooled across 251 studies, raw follower count is a weak and unreliable guide to what actually predicts results. What consistently predicts attention, interest, and buying intent is a trusted influencer, a genuine fit with the brand, and content worth watching, not the size of the following.

Data chart

What actually drives influencer results, ranked

Content Is Enjoyable0.65Content Is Useful0.55Audience Trusts Creator0.51Creator Fits Brand0.45Raw Follower Count-0.28 (n.s.)

A trusted, well-matched creator predicts results far more strongly than a big following does.

Action guide

  1. Select for trust and brand fit first; treat follower count as a tiebreaker.Trust and fit predict attitude, engagement, and purchase intent far more reliably than reach does. The evidence thins out for actual purchases, and thinnest of all for brand fit, where only two studies measured purchase behavior, so treat the fit half of this as directional.
  2. Fund content quality, both useful and entertaining.Strong content is the single biggest driver of buying interest in this research.
  3. Match content to the platform.Post and influencer-content effects run stronger on content-focused, utilitarian platforms. The study grouped platforms into types rather than testing each one, so treat that as a rule of thumb, not a hard rule.
  4. Keep disclosing sponsored posts.Average response does not drop when you do, so honest labeling costs you nothing measurable here.
  5. Watch active engagement, not just impressions.Engagement is the outcome most closely linked to eventual purchase across these studies.

Evidence

  • Raw follower count is a weak, unreliable guide to attention, interest, or purchases.
  • Perceived credibility, how much an audience trusts the creator, is the most consistently strong correlate of attitude, engagement, and purchase intention, and the link holds just as strongly for actual purchase behavior.
  • A genuine fit between the influencer and the brand strongly predicts attitude and interest.
  • Content people find useful and enjoyable is the top driver of buying intent.
  • Labeling a post as "sponsored" shows no average effect, up or down, on response.
  • Platform changes how much the content does: post and influencer-content effects run stronger on content-focused, utilitarian platforms. How much the audience trusts the creator works about the same across the platform types studied.

Key takeaway

Buy trust and fit, not follower count; that is what consistently predicts influencer-marketing results.

Source

Pan, M., Blut, M., Ghiassaleh, A., & Lee, Z. W. Y. (2025). Influencer marketing effectiveness: A meta-analytic review. Journal of the Academy of Marketing Science, 53(1), 52–78. https://doi.org/10.1007/s11747-024-01052-7

Read the paper ↗

Evidence strength: Strong for attention, interest, and buying intent (pooled across 251 studies, 27 countries); thinner for direct sales, and the results describe what moves together, not proven cause-and-effect or ROI.