The article deals with the problems of the popularity of online encyclopedias in the nowadays information space. It is shown that the most popular in Ukraine is Wikipedia, and the academic Encyclopedia of Modern Ukraine is much inferior to it in this context. The different levels of popularity these two compendiums of knowledge are explained in terms of the belonging of each of them to different types of cultures: the point here is pop culture and high culture, which differ in a priori by many indicators, including a popularity among people.