INFLUENCER MARKETING

Harvard study reveals hidden costs of sponsored content for influencers

By our African Marketing Confederation News Team | 2025

Researchers identify a ‘reputation-burning effect’ – a measurable decline in subscriber count following sponsored posts.

In an era in which influencer marketing dominates digital platforms, a study published in the journal Management Science unveils a surprising reality: sponsored content can harm an influencer’s reputation and reduce audience engagement.

Photo by George Milton from Pexels

Analysing thousands of YouTube videos from top beauty and style influencers, researchers uncovered what they call a ‘reputation-burning effect’ – a measurable decline in subscriber count following sponsored posts. 

 

Compared to equivalent organic, unsponsored content, posting a sponsored video leads to an average 0.19% decrease in an influencer’s subscriber count. Although that percentage may seem small, for influencers with millions of followers, even minor losses can have significant financial and reputational consequences. 

 

This effect was particularly pronounced for larger influencers, suggesting that the more popular the creator, the higher the stakes. 

 

Marketing efforts may not lead to the desired outcomes 

 

“If consumers don’t perceive influencers as trustworthy and authentic, much of their marketing efforts may not lead to the desired outcomes,” says Mengjie (Magie) Cheng, co-author and doctoral student at Harvard University. 

 

The study, titled ‘Reputation Burning: Analysing the Impact of Brand Sponsorship on Social Influencers’, also identified strategies that can mitigate the negative impact of sponsorships: 

 

  • Content Alignment Matters: Sponsored content that closely matches an influencer’s typical style is more accepted by audiences. 

 

  • Smaller Brands Have an Advantage: Promotions for lesser-known brands tend to result in less audience backlash compared to high-profile brand deals. 

 

For brands, the research challenges the assumption that bigger audiences mean better marketing results. 

 

“Our work highlights that bigger isn’t always better when it comes to choosing influencers,” says Shunyuan Zhang, co-author and professor at Harvard University. “Brands need to think beyond follower counts and consider audience trust and alignment with the influencer’s content.” 

 

The findings also suggest a role for social media platforms. By encouraging influencers to balance sponsored and organic content, platforms can help maintain audience trust, reduce disengagement and sustain long-term engagement. 

 

You can find out more about the study here.

View all articles »