Ancient graffiti have traditionally been studied as brief texts, but that is only part of the information they communicate. I propose a more comprehensive approach that considers their content and form and situates them more firmly within their physical and social environment. Engaging more closely with the spatial context of graffiti informs us about the ancient use of space and the human activity within it. It also allows us to see what else, besides text, was inscribed on the walls of Pompeii. The concept of the dialogue offers a flexible model of inquiry and provides a fresh perspective for examining the numerous graffiti of a residential space. From number games to drawings to clever compositions of poetry, the graffiti of the House of Maius Castricius reveal wide participation and a strong interest in the act of writing, a popular activity here and throughout Pompeii.