Study: Public Health Ad Spending May Fund Misinformation Sites
A cross-sectional study published in JAMA Network Open found that government agencies and health organizations spent an estimated $35.7 million on advertising placed on websites flagged for publishing health misinformation between 2021 and 2024. The research indicates this spending may inadvertently fund the spread of false content, though expenditures from these sources declined over the study period.
How the Study Was Conducted
The analysis examined digital advertising expenditures from January 2021 to December 2024 by integrating two commercial datasets.
- Identifying Misinformation Sites: Researchers used data from NewsGuard, a service that rates website credibility, to identify 1,229 news websites flagged for repeatedly publishing health misinformation. Health misinformation is defined as false or misleading content inconsistent with the best available scientific evidence.
- Tracking Ad Spending: Advertising expenditure data was sourced from MediaRadar's MediaRadar360 database, a commercial advertising intelligence platform. Of the 1,229 flagged websites, advertising data was available for only 11.
Key Findings
The analysis of the 11 websites with available data yielded the following results:
Total advertising spending across these 11 websites was $336.4 million during the four-year period. Government agencies and health organizations contributed $35.7 million, representing approximately 10.6% of the total.
- Spending Concentration: The majority of advertising was concentrated on two websites: NewsMax and ZeroHedge. These two sites accounted for 65.2% of all advertising expenditures and 67.3% of the spending from government and health organizations.
- Revenue Share: The median advertising expenditure from government and health organizations per website was $1.39 million, representing about 9.7% of each site's total advertising revenue. One website, Healthy and Natural World, was an outlier where government and health advertisers accounted for 25.7% of its total ad spend.
- Declining Trend: Advertising expenditures from government and health organizations on these sites decreased from $16.7 million in 2021 to $6.8 million in 2024.
- Advertiser Breakdown: Among specific advertiser types within the government and health organization category, nonprescription remedy and wellness product advertisers spent $19.2 million. Medical and health insurance companies spent $571,843.
Website Content and Context
The 11 websites in the analysis published content across multiple categories, including political news and commentary, conspiracy theories or hoaxes, health or medical information, and general news.
The study's background notes that advertising revenue is considered a primary economic driver for websites publishing online misinformation. Previous analyses have documented that advertisements, often placed through automated programmatic ad-buying systems, can appear on sites hosting false content.
Study Limitations
The researchers noted several limitations to their analysis:
- Advertising expenditure data was available for only 11 of the 1,229 websites flagged for health misinformation.
- There was limited visibility into certain digital advertising formats; online video data was accessible for only 2 websites, and mobile application data for only 1.
- The study had no data on the proportion of content on each website that constituted health misinformation.
Conclusions and Recommendations
Based on the findings, the study authors concluded that government and health organizations may be inadvertently funding websites that publish health misinformation through routine advertising placements. They suggested this risks lending credibility to false content and eroding public trust.
The researchers recommended that policymakers consider implementing stronger advertising restrictions to prevent public health dollars from supporting the spread of misinformation.