New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New INFORMS journal Marketing Science Article Key Takeaways:

• Over 95% of sponsored influencer posts on Twitter were not disclosed.
• Influencer sponsorship arrangements with younger brands are less likely to be disclosed.
• A large number of consumers can’t detect the sponsorship arrangement without disclosure.
• The consumer-protection regulatory environment around undisclosed sponsorships has lagged behind.

BALTIMORE, MD, April 3, 2025 – New research in the peer-reviewed journal Marketing Science has found that 95% of influencer posts on Twitter (now X), which are sponsored, are not disclosed.

The peer-reviewed article, “How Much Influencer Marketing Is Undisclosed?,” has been published in the INFORMS journal Marketing Science. The authors of the study are Daniel Ershov from University College London and the Center for Economic Policy Research in London; Yanting He from Imperial College London; and Stephan Seiler from the Center for Economic Policy Research and Imperial College London.

The researchers further found that when compared with posts that disclose a sponsorship arrangement, undisclosed posts tend to be associated with young “brands” with a large social media following.

“Our study fundings highlight a potential need for further regulatory scrutiny,” says He.

What is Influencer Marketing?

Influencer marketing is an emergent means to reach the consuming public through alternative channels to traditional advertising, such as broadcast and print media. Influencer marketing leverages private individuals to promote brands, products or services, in which those individuals are compensated for their endorsements. Typically, “influencers” are selected on the basis of their large social media followings and/or celebrity status.

“Because consumers might find it difficult to distinguish paid influencer posts from genuinely organic content, regulators in many countries now require any paid content to be disclosed,” says Ershov. “But because of the novelty associated with influencer marketing, the evolving regulatory framework has not caught up.”

About This Study

Study researchers used a novel dataset of over 100 million brand-related posts on Twitter from 268 brands, along with a new text-based classification approach that identified undisclosed sponsored content. They then quantified the overall importance of undisclosed influencer posts to evaluate whether consumers could detect undisclosed commercial content. They tracked the evolution of undisclosed posts over time, and were able to identify the brands from which undisclosed posts originated.

“We found that a large number of participants in an online survey were not able to identify commercial content when that content did not provide disclosure,” says Seiler. “We also demonstrated that although regulation did tighten up over our sample period from 2014 to 2021, the share of undisclosed content decreased only slightly.”

In addition, the researchers found that undisclosed sponsored posts tended to originate from younger brands with large Twitter followings.

Link to Study.

About INFORMS and Marketing Science
INFORMS is the world’s largest association for professionals and students in operations research, AI, analytics, data science and related disciplines, serving as a global authority in advancing cutting-edge practices and fostering an interdisciplinary community of innovation. Marketing Science, a peer-reviewed journal published by INFORMS, focuses on quantitative research at the intersection of consumers and firms. INFORMS fosters smarter decision-making and innovation through its journals, conferences and professional resources. Learn more at www.informs.org or @informs.

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