Multi-product ads (MPAs) allow an ad platform to display multiple products within a single ad unit. Unlike a single-product display ad, similar ads from the same product category may appear in MPAs and induce consumer satiation. Further, the simultaneous display of ads from multiple product categories can result in cross-category complementarity or substitution in consumers’ utility from ad-clicking. This study examines ad platforms’ potential benefit from incorporating consumer within-category satiation and cross-category spillover into ad-serving policies. To achieve this goal, the authors propose a full-equilibrium modeling framework to capture both the demand (i.e., consumers’ clicks) and supply sides (i.e., advertisers’ bids) of MPAs. The results from a dataset from a large display ad network reveal heterogeneity in within-category satiation across consumers and categories, and provide evidence of cross-category complementarity. The authors then demonstrate how the platform can indirectly influence the ad variety and category composition of MPAs through three counterfactuals of ad-serving policy changes. The results show that the implementation of a more privacy-preserving policy may hurt both consumer welfare and the platform’s revenue because of the reduced ad variety, which makes consumers more prone to within-category satiation and less prone to cross-category complementarity.

中文翻译：

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EXPRESS：多产品广告中的品类内饱和和跨品类溢出


多产品广告 (MPA) 允许广告平台在单个广告单元中展示多种产品。与单一产品展示广告不同，同一产品类别的类似广告可能会出现在 MPA 中并引起消费者满意。此外，同时显示来自多个产品类别的广告可以导致消费者通过广告点击获得的效用的跨类别互补或替代。本研究探讨了广告平台将消费者的品类内满意度和跨品类溢出纳入广告服务政策的潜在好处。为了实现这一目标，作者提出了一个完全均衡的建模框架来捕获 MPA 的需求方（即消费者的点击）和供给方（即广告商的出价）。大型展示广告网络数据集的结果揭示了消费者和类别之间的类别内满意度的异质性，并提供了跨类别互补性的证据。然后，作者展示了该平台如何通过广告服务政策变化的三个反事实间接影响 MPA 的广告品种和类别构成。结果表明，实施更加保护隐私的政策可能会损害消费者福利和平台收入，因为广告种类减少，这使得消费者更容易产生品类内的满足感，而不太容易产生跨品类的互补性。