The theme of Russian Neo-Paganism or, as it is often called, Rodnoverie, has become prominent in academic periodicals which does not necessarily reflect the real level of Neo-Paganism’s popularity in the Russian society. Researchers are not able to convincingly estimate the number of its adherents. Sociological surveys are too contradictory, and we can try to rely upon the data collected on the Internet. Some authors have already used these data by counting the number of Neo-Pagan groups and followers in the social networks. The purpose of this paper is to assess the validity of such calculations. After having monitored various religious groups in such popular Russian social services as the Odnoklassniki and VKontakte for a few years, the author shows that this method of calculation is inefficient and can lead to errors. Therefore, the actual number of adherents of the Russian Neo-Paganism remains unknown even approximately.