This paper focuses on preschool teachers' use of online social networks for discussions about tablets in preschools. Posts initiating discussions (n = 465) were analysed to increase understanding of what questions tablets raise among preschool teachers and to understand online communication from a professional development perspective. Posts were analysed using thematic analysis in combination with the Technological Pedagogical Content Knowledge framework, which illustrates what kind of knowledge teachers need in order to teach efficiently with technology. The results indicate that traditional means of professional development are frequently discussed but that the newness of tablets in preschools makes it difficult for preschool teachers to find support in research, training and literature. Thus, communication can partly be described as collegial support. Questions often aim at urgent and specific forms of desired knowledge, possibly challenging to address by acts of reading literature, attending courses or lectures. Furthermore, market interests become visible, as providers of services and products promote lectures, books, websites and applications. As rapidly changing technologies enter the preschool practice, it seems that preschool teachers will increasingly be dependent on more direct and flexible forms of professional development. (author abstract)