Inferno: A Guide to Field Experiments in Online Display Advertising

Abstract

Online display advertising is a hostile medium for field experiments. Display ad effects are tiny and necessitate large-scale experiments. The experimenter has limited control because ad exposure is jointly determined by advertisers, users, algorithms, and market competition. As such, online display ads provide useful lessons for experimenters at the frontier of digital research more generally. Display-ad experiments place renewed focus on old topics like statistical power and compliance as well as on new issues like identity fragmentation and market spillovers. In this guide, we review these challenges, best practices, and new developments.

Keywords: field experiments, advertising effectiveness, digital advertising

JEL Classification: C93, M37