The proliferation of online resources and an increase in accessibility has led teachers to go online to connect, share ideas and expand their own professional learning opportunities on social media platforms. Over the last five years there has been a resurgence in this field to research what teachers are doing in and with social media. Knowing that teachers are networking or collecting resources misses the fundamental premise for such action, which in turn, does little for understanding social media use as a professional learning activity. This study takes one step back, to investigate the reasoning for particular social media use. Through a qualitative paradigm, expert ICT teachers were interviewed about their conceptualisations of professional learning and related activities online. These recognized ICT-experts from Australia, Europe and United States of America were purposely selected due to a personal and professional impetus to maintain currency with innovative ideas in this ever-changing field. These expert teachers engaged in social media in different ways based on their conceptualisations of professional learning in these online spaces. The findings present a typology of reasoning based along two continuums, Self and Interactivity. These axioms defined four categories of teacher engagement online: Info-consumer; info-networker; self-seeking contributor; and vocationalist. A new paradigm of professional development is presented which has important implications for understanding the role of social media in teacher professional learning as well as in reshaping what we consider as effective professional development.