A significant portion of the online activities of a modern man is associated with the space of social media, where his need to demonstrate his competence, to be recognized by other users, and to possess information is realized. For libraries, such a space is a vital tool of ensuring interactions with users, allowing them the organization of activities to inform subscribers, create and publish content related both to the promotion of library and information resources and services, and to the formation of the image of the library as a whole. However, there are problems related to user engagement on pages and in library groups. The purpose of this work is to describe marketing technologies that allow the creation of favorable conditions for the development of discussion among users of social networks and increasing their activity on the pages of libraries, which has a favorable effect on the coverage of basic, informational records. Contests, quizzes and promotions are offered as such technologies. An analysis of the ‘VKontakte’ pages of the fourteen largest libraries in Russia showed that these forms are not widespread enough in the online environment: libraries prefer to advertise offline promotions, contests and quizzes, rather than conduct them on the social media platform. The following important criteria for the implementation of these technologies are identified: the use of direct appeals to the audience with the positive emotional coloring; topics that allow one to show his social activity, as well as those close to the interests of the audience. Thus, these criteria should be taken into account when libraries conduct contests, quizzes and promotions in social media.