Media scholars have studied and critiqued search engines – and in particular the dominant commercial actor, Google – for over a decade. Several conceptual and methodological problems, such as a lack of technological transparency, have made a detailed analysis of concrete power relations and their effects difficult. This paper argues that a microeconomic approach can aid media scholars in examining the complex interactions that underpin the dynamics of information visibility unfolding around the Google search engine. Using the concept of a ‘three-sided market’, we characterize the business model built around google.com as the foundation of the company’s success. We then argue that the combination of search and advertising services, and in particular advertising network services, creates powerful incentives to orient the results page in self-serving ways, leading to fundamental conflicts of interest exacerbated by Google’s dominant position in both markets. Based on search engines’ mass media-like capacity to shape public discourse, we consider the identification of economic forces both as a prerequisite for a robust critique of the current situation and as a starting point for thinking about regulatory measures.