BACKGROUND: Influencer-based social media marketing campaigns are a popular strategy to engage customers in many non-research industries (e.g., retail), but have been increasingly used in public health campaigns to reach and engage specific populations. However, few studies have directly compared the performance of influencer-based marketing with other ad strategies (e.g., paid ads) in achieving these goals. METHODS: From March to September 2023, we conducted an influencer-focused marketing campaign in which we identified and partnered with predominantly Black LGBTQ + influencers in the United States South to promote engagement in our ongoing research. We then used web analytics and interest form data to compare performance of influencer posts versus paid ads over the same time period. RESULTS: We contacted a total of 358 influencers, 20 of whom ultimately agreed to post (85% Black/African American) and made a total of 28 posts on our behalf. A significantly higher percentage of users who clicked through influencer posts were Black (40% vs. 15%), were not currently using pre-exposure prophylaxis (PrEP) (67% vs. 62%), had no history of PrEP use (78% vs. 72%), and reported higher medical mistrust (12% vs. 8%) compared to those who clicked through paid ads. The percentage of Black men who have sex with men who were at high HIV risk, who were not taking PrEP, had no history of PrEP, or were high in mistrust, were all 2-3 times higher among those who clicked through influencer posts relative to paid ads. CONCLUSIONS: Influencer-focused marketing may be a powerful tool to efficiently reach and engage high-priority and hard to reach populations.