Social advertising is the most important channel of mass communication that shapes public opinion. However, its effectiveness is often questioned, which necessitates the search for ways to increase its communicative impact on the target audience. The most important is the study of the sociolinguistic characteristics of advertising influence in the youth environment, since at this age there are simultaneously risks of socialization and flexibility of thinking - a tendency to reflection, reassessment of values. The article presents the results of a study that reveals the main communicative characteristics of Russian social advertising and the mechanisms of its influence on the behavior of student. The empirical research methods were a questionnaire survey of students of the Financial University, as well as an analysis of advertising videos and comments posted under them on YouTube and VKontakte. As a result of the study, it was revealed that the youth audience is well versed in the concept of social advertising. At the same time, most of the students' attention is attracted by bright, provocative (shocking) social advertising, which is a mini-film about the life of real heroes. The most memorable topics relate to the fight against «bad» habits, maintaining a healthy lifestyle, compliance with the law. Based on the results of the study, as well as the experience of Russian and foreign scientists, the article concludes with recommendations for enhancing the effectiveness of social advertising. The importance of adhering to the principles of unambiguity, conciseness and synchronism of social advertising, «soft» chrakter, honesty and openness is indicated. The findings of the study may be useful to specialists in advertising and public relations, sociologists and specialists in of social work.