Cookie monsters. Anatomy of a digital market infrastructure

The aim of this article is to examine the market arrangements built by the online marketing industry around small pieces of data now ubiquitous in digital markets–namely “http cookies.” We show how cookies have become the backbone and the main vehicle of a vast market infrastructure, based on its ability to transform online behavioral information into data assets, and to attach these assets to advertising products. We examine the complex trading operations that are implemented from the elementary brick that constitutes the cookie. We also raise the question of the strength and durability of this infrastructure, at a time when it is disputed and seems weakened. Beyond the particular case of cookies, we identify three main operations that market infrastructures typically support: knowledge production, capitalization, and coordination. We also highlight the centrality of “datafication” (tracking, “data lake” building, matching, etc.) in the process of market digitalization. We thus contribute to the framing of the concept of (digital) market infrastructure.