KP-Agent: Keyword Pruning in Sponsored Search Advertising via LLM-Powered Contextual Bandits
Hou-Wan Long, Yicheng Song, Zidong Wang, Tianshu Sun
TL;DR
This paper tackles keyword pruning in sponsored search advertising by framing it as a contextual bandit problem and introducing KP-Agent, an LLM-based agent augmented with SSA-domain tools and a memory module. The system uses domain-specific tools to process tabular SSA data without hallucination, a memory-augmented reflection mechanism for few-shot learning, and code generation to enact pruning decisions, all guided by advertiser-side KPIs. Empirical evaluation on 21 days of Meituan SSA data shows KP-Agent achieves up to 49.28% higher cumulative profit than baseline pruning strategies, with larger gains when the minimum keyword retention is lower. The work demonstrates a practical, adaptive pruning approach that improves resource allocation under budget constraints and demonstrates significant potential for real-world SSA optimization.
Abstract
Sponsored search advertising (SSA) requires advertisers to constantly adjust keyword strategies. While bid adjustment and keyword generation are well-studied, keyword pruning-refining keyword sets to enhance campaign performance-remains under-explored. This paper addresses critical inefficiencies in current practices as evidenced by a dataset containing 0.5 million SSA records from a pharmaceutical advertiser on search engine Meituan, China's largest delivery platform. We propose KP-Agent, an LLM agentic system with domain tool set and a memory module. By modeling keyword pruning within a contextual bandit framework, KP-Agent generates code snippets to refine keyword sets through reinforcement learning. Experiments show KP-Agent improves cumulative profit by up to 49.28% over baselines.
