Bid optimization using maximum entropy reinforcement learning

Real-time bidding (RTB) has become a critical way for online advertising. It allows advertisers to display their ads by bidding on ad impressions. Therefore, advertisers in RTB always seek an optimal bidding strategy to improve their cost-efficiency. Unfortunately, it is challenging to optimize the bidding strategy at the granularity of impression due to the highly dynamic nature of the RTB environment. In this paper, we focus on optimizing the single advertiser's bidding strategy using a stochastic reinforcement learning (RL) algorithm. Firstly, we utilize a widely adopted linear bidding function to compute every impression's base price and optimize it with a mutable adjustment factor, thus making the bidding price conform to not only the impression's value to the advertiser but also the RTB environment. Secondly, we use the maximum entropy RL algorithm (Soft Actor-Critic) to optimize every impression's adjustment factor to overcome the deterministic RL algorithm's convergence problem. Finally, we evaluate the proposed strategy on a benchmark dataset (iPinYou), and the results demonstrate it obtained the most click numbers in 9 of 12 experiments compared to baselines. (c) 2022 Elsevier B.V. All rights reserved.