At its core, the power of the public intellectual is the capacity to make ideas move through a culture. This article looks at what kind of academic persona - that is, what kind of public self whose original status comes from intellectual work and thinking - navigates effectively through online culture and communicates ideas in the contemporary moment. Part of the article reports on a research project that has studied academic personas online and explores what can be described as 'registers of online performance' that they inhabit through their online selves. The research reveals that public intellectuals have to interpret effectively that online culture privileges what is identified as 'presentational media': the individual as opposed to the media is the channel through which information moves and is exchanged online, and it is essentially a presentation of the self that has to be integrated into the ideas and messages. From this initial analysis/categorisation of academic persona online, the article investigates the online magazine The Conversation, which blends journalism with academic expertise in its production of news stories. The article concludes with some of the key elements that are part of the power of the public intellectual online.