Social Navigation is an emerging approach to enhance online learning content. With social navigation, users can be guided through large volumes of learning material by visual cues, which integrate the browsing history of past users. This allows users to easily identify the most important content fragments, which attracted more attention from similar users. Social navigation in classical hypermedia such as hypertext has shown to increase learners' motivation and helped users to discover most valuable information. This paper presents our attempt to extend the benefits of social navigation beyond its traditional scope. We developed a footprint-based social navigation approach for time-based continuous media, a popular kind of educational content in lecture recording systems. We implemented this approach in the web lecture system virtPresenter and evaluated it in a two-semester long classroom study. The results show that the social navigation cues significantly affect user lecture na...