Bidding Through the Lens of Attribution: Pick the Right Labels!

Summary Attribution-the mechanism that assigns conversion credits to individual marketing interactions-is one of the foremost digital marketing research topic. Indeed, attribution is used everywhere in online marketing whether for budget decisions or for the design of algorithmic bidders that the advertiser relies on to buy inventory. Still, an attribution definition over which everyone in the marketing community agrees upon is yet to be found. In this paper, we focus on the problem faced by a bidder who is subject to an attribution black box decided by the advertiser and needs to convert it into a bid. This naturally introduces a second level of attribution, performed internally by the bidder. We first formalize an often implicitly used solution concept for this task. Second, we characterize the solution of this problem which we call the core internal attribution. Moreover, we show it can be computed using a fixed-point method. Interestingly, the core attribution is based on a notion of marginality that differs from previously used definitions such as the counterfactual marginality.