A small subset of information visualization and the digital humanities focuses on casual users, that is, users in everyday, non-work contexts. The development of digital cultural heritage collections like Europeana.eu for the general public increases the importance of this user group. This position paper reviews parallel findings from both research fields on casual users, their goals and exploration behavior: Casual users often come without concrete information needs, they rather search for something interesting and engaging. They browse through the information until they find something worth exploring in detail. From these characteristic needs and behavior of casual users we delineate design requirements for public information visualizations in the digital humanities. We discuss how further exchange between these two fields of research can bring forward both fields.