ICL-Bandit: Relevance Labeling in Advertisement Recommendation Systems via LLM

Lu Wang, Chiming Duan, Pu Zhao, Fangkai Yang, Yong Shi, Xuefeng Luo, Bingjing Xu, Weiwei Deng, Qingwei Lin, Dongmei Zhang


Abstract
Measuring the relevance between user queries and advertisements is a critical task for advertisement (ad) recommendation systems, such as Microsoft Bing Ads and Google Ads. Traditionally, this requires expert data labeling, which is both costly and time-consuming. Recent advances have explored using Large Language Models (LLMs) for labeling, but these models often lack domain-specific knowledge. In-context learning (ICL), which involves providing a few demonstrations, is a common practice to enhance LLM performance on domain-specific tasks. However, retrieving high-quality demonstrations in a vast exploration space remains challenging. In this paper, we introduce ICL-Bandit, a practical and effective approach that leverages ICL to enhance the query-ad relevance labeling capabilities of LLMs. We develop a novel bandit learning method to identify and provide superior demonstrations for ICL, thereby improving labeling performance. Experimental results demonstrate that ICL-Bandit achieves state-of-the-art performance compared to existing methods. Additionally, ICL-Bandit has been deployed in Company X, that serves billions of users worldwide, confirming its robustness and effectiveness.
Anthology ID:
2025.findings-emnlp.1273
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
23439–23449
Language:
URL:
https://aclanthology.org/2025.findings-emnlp.1273/
DOI:
Bibkey:
Cite (ACL):
Lu Wang, Chiming Duan, Pu Zhao, Fangkai Yang, Yong Shi, Xuefeng Luo, Bingjing Xu, Weiwei Deng, Qingwei Lin, and Dongmei Zhang. 2025. ICL-Bandit: Relevance Labeling in Advertisement Recommendation Systems via LLM. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 23439–23449, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
ICL-Bandit: Relevance Labeling in Advertisement Recommendation Systems via LLM (Wang et al., Findings 2025)
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https://aclanthology.org/2025.findings-emnlp.1273.pdf
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