University lectures are increasingly recorded or reproduced and made available to students online. This paper aggregates and critically reviews the associated literature, thematically organised in response to four questions. In response to the first question--does student attendance decrease when online content is made available--research indicates that students primarily use digital content for review and revision rather than as a substitute for on-campus attendance. Analysis of the research in response to the second question--is achievement affected when attendance is face-to-face versus online--revealed no empirically supported significant difference. The third question was whether online content is better suited to some pedagogical tasks than others. A predominant theme in the literature is that digital content has potential as a disruptive pedagogy, accelerating an overall shift from didactic lecture to constructivist learning. Analysis revealed a research gap around the fourth question--is there evidence that some online formats are particularly suited to advancing learning. The few published comparative studies revealed contradictory results. Overall conclusions from the combined questions are that online digital content is a worthwhile learning and teaching pursuit and discipline and context must be considered in designing the particular approach.