When the Ad Becomes the Story: A 14-Day Comparison of Audience Discourse on a Celebrity-Endorsed Sports Prediction Market Advertisement and an Earlier Campaign by the Same Endorser

Abstract Celebrity endorsement is a prominent feature of sports betting marketing, but little is known about what audiences say about gambling, risk, and responsible gambling when they respond to such advertisements in open social media settings. This study analyzed the public YouTube comments and replies posted within 14 days of the release of a sports prediction market advertisement (n = 4,425) and of an earlier apparel advertisement featuring the same endorser (n = 13,267). Comment counts and timing were computed for the full corpus. Sentiment and topical codes were independently double-coded, blind to each other's judgments, by two subject-matter experts unaffiliated with the study (a legal scholar and a scholar of economics and business) for random samples of 120 comments per campaign and for every prediction market comment flagged by a keyword screen (n = 350). In the prediction market campaign, 187 comments (4.2%; 95% CI 3.67–4.86) concerned gambling, betting, or trading; 23 (0.5%) mentioned risk or harm, and none referred to the responsible gambling legend that the video displayed. Controversy-related discourse was less frequent than in the apparel campaign (20.8% vs 48.3%), as were product references (4.2% vs 16.7%), whereas sexualization codes were equal (10.0% each). Comment volume peaked on days 5 and 6, which coincided with international press coverage and athletes' criticism. The findings describe expressed discourse, not attitudes, exposure, or behavior, and are limited by small coded samples and by the comparison design.