A major challenge of our time is reducing disparities in access to and effective use of digital technologies, with recent discussions highlighting the role of AI in exacerbating the digital divide. We examine user characteristics that predict usage of the AI-powered conversational agent ChatGPT. We combine web tracking and survey data of N=1068 German citizens to investigate differences in activity (usage, visits and duration on this http URL). We examine socio-demographics commonly associated with the digital divide and explore further socio-political attributes identified via stability selection in Lasso regressions. We confirm lower age and more education to affect ChatGPT usage, but not gender and income. We find full-time employment and more children to be barriers to ChatGPT activity. Rural residence, writing and social media activities, as well as more political knowledge, were positively associated with ChatGPT activity. Our research informs efforts to address digital disparities and promote digital literacy among underserved populations.