This thesis aims to uncover the reasons behind the sudden rise of the YouTube celebrity and to test (by means of an experimental study of teenager interests) media claims that YouTubers have become more popular among teenagers than any traditional type of celebrity. The thesis integrates YouTubers into celebrity studies by first outlining the origins of celebrity and its general role in society and then drawing parallels between traditional types of celebrity and YouTubers via describing the characteristics they embody and the specific roles they perform. As a result, YouTubers are found to be a technologically determined next step in the evolution of the TV personality, whose celebrity is mainly structured around the concepts of familiarity and intimacy. What follows is a discussion of participatory culture, monetization and doing YouTube as a job, with emphasis on the effects these developments had on the rise of the YouTube celebrity and online content & culture in general. The thesis is concluded by an experimental study conducted using quantitative research methods on a sample of over 5,000 Czech teenagers by analyzing their Facebook page-likes. The results suggest that YouTubers really are more important to teenagers than traditional celebrities.