Digital advertising is central to the business models and technological affordances of digital platforms, creating marketplaces for user attention. Despite the keen theoretical attention to the commodification of audiences in critical new media and data studies, there has been little exploration of how digital marketing can also be understood as a methodological lens to study both controversies and the practices involved in the commodification of attention around the issues that animate such controversies. Addressing this gap in knowledge by drawing on the digital methods approach, this article proposes repurposing the tools, data and practices of digital marketing – what we coin digital marketing epistemology – as new methodological points of observation in controversy mapping. Focusing empirically on Google Ads, we scrutinize the building blocks of advertising campaigns on the platform and their metrics and measurements. We then offer a set of methodological ‘recipes’ for repurposing the Google Ads platform for controversy mapping and illustrate through a series of data sprints how this can contribute not only to a better understanding of the measurement and valuation practices that are involved in converting attention into a tradable asset but also the role these practices play in the unfolding of techno-social controversies.