The article defines the principles of successful interaction between the lecturer and the Internet audience, in particular, their ability to accurately predict the addressee’s characteristics in order to choose the most appropriate means of their persuasion. In modern linguistics the factors of communication effectiveness include the type of the addressee and the conditions of their communication with the addresser. Extensive expertise allows the lecturer to make an accurate assumption about the average level of university students’ knowledge at all levels of their education. Modern technologies provide an unprecedented opportunity to share scientific knowledge with an extremely heterogeneous Internet audience. As a result, the genre of the lecture is constantly evolving, successfully adapting to new conditions, moreover, it becomes particularly relevant as a means of rational cognition of the reality. Based on Russian and English YouTube video transcripts, the article attempts to analyze the mechanisms of evolutionary changes the lecture genre undergoes in the Web. Having studied the entertaining parascientific lectures, science vs. pseudoscience debates, popular science talks and university online lectures, the author argues that e­lecture effectiveness is largely determined by the speaker’s ability to create an informative, enjoyable, audience­-engaging content and encourage Internet users to research the subject further themselves. Taken together, the evidence suggests that in the digital era e­lectures are transformed into an element of the popular culture and are complimentary to the traditional education. The findings may be useful for improving students’ communicative competence.