While the auto-bidding literature predominantly considers independent bidding, we investigate the coordination problem among multiple auto-bidders in online advertising platforms. Two motivating scenarios are: collaborative bidding among multiple bidders managed by a third-party bidding agent, and strategic bid selection for multiple ad campaigns managed by a single advertiser. We formalize this coordination problem as a theoretical model and investigate the coordination mechanism where only the highest-value bidder competes with outside bidders, while other coordinated bidders refrain from competing. We demonstrate that such a coordination mechanism dominates independent bidding, improving both Return-on-Spend (RoS) compliance and the total value accrued for the participating auto-bidders or ad campaigns, for a broad class of auto-bidding algorithms. Additionally, our simulations on synthetic and real-world datasets support the theoretical result that coordination outperforms independent bidding. These findings highlight both the theoretical potential and the practical robustness of coordinated auto-bidding in online auctions.

翻译：尽管自动投标文献主要考虑独立投标，我们研究了在线广告平台中多个自动投标者之间的协调问题。两个驱动场景是：由第三方投标代理管理的多个投标者之间的协作投标，以及由单个广告主管理的多个广告活动的战略性出价选择。我们将这一协调问题形式化为一个理论模型，并研究了一种协调机制：只有最高价值的投标者与外部投标者竞争，而其他协调投标者则避免竞争。我们证明，对于一大类自动投标算法，这种协调机制优于独立投标，既提高了投入产出比（RoS）的合规性，也增加了参与自动投标者或广告活动的总价值。此外，我们在合成数据集和真实世界数据集上的模拟支持了协调优于独立投标的理论结果。这些发现凸显了在线拍卖中协调自动投标的理论潜力和实际稳健性。