Online Advertising and Antitrust: Network Effects, Switching Costs, and Data as an Essential Facility

In this paper, I discuss some of the traditional sources of market power grounded in economics, and how they apply to online advertising markets. I discuss the idea that digital advertising has evolved technologies that are intended to dismantle many early network effects in online advertising. I then discuss how new digital technologies have evolved to reduce switching costs for advertisers. Last, I discuss briefly the question of whether data can be thought of as an essential facility for advertising.