The paper investigates factors commonly associated with “post-truth” political PR via social media: viral communication, fake news, and social bots, applied to the 2017 French presidential elections. Empirical research sheds light on these problematic notions and examines the social and technical dynamics of online political deliberation, to better understand their implications for political PR. Relatively little “fake” information featured among the most popular retweets during this period. The expression of opinions, humour and irony, as well as denunciations of fakes and scandals, appear more likely to spread “virally”. Some social bot activity was detected, but this is increasingly hard to distinguish. Implications for communications include insights into the types of contents likely to spread virally, if other conditions (e.g. network structure and visibility) are fulfilled. The study is original in linking virality and message contents, in the methodology of bot detection, and in bringing together three factors generally treated separately. It provides insights to researchers and political PR professionals.