SPAR: Experience-Driven Strategy Evolution in Multi-Session B2B Sales

Hangming Zhang, Yao Zhao, Haotian Kuang, C.L.Philip Chen, Tong Zhang, Tengyue Ma


Abstract
B2B outbound sales involves high transaction values and relationship-based trust, so closing a deal typically requires multiple rounds of outreach building on prior context. Existing LLM-based sales agents operate within single sessions and cannot carry forward context or refine strategies from experience. Methods that do learn from experience store lessons as unstructured text and treat all outcomes as equally informative, with no mechanism to distinguish a flawed strategy from an external factor. We propose SPAR, a self-evolving framework that models selling strategies as testable hypotheses and refines them without parameter updates. A double-loop architecture lets an inner loop adapt to individual merchants through episodic memory while an outer loop evolves a shared strategy playbook through causal attribution and hypothesis-driven evolution. In a live A/B test on the 1688 platform with over 200,000 merchants, SPAR achieves +15.8% conversion lift and +35.8% high-intent merchant growth. Human evaluation by domain experts rates SPAR at 4.62 out of 5 on overall sales quality, the highest among all methods.
Anthology ID:
2026.emnlp-industry.54
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
892–901
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.54/
DOI:
Bibkey:
Cite (ACL):
Hangming Zhang, Yao Zhao, Haotian Kuang, C.L.Philip Chen, Tong Zhang, and Tengyue Ma. 2026. SPAR: Experience-Driven Strategy Evolution in Multi-Session B2B Sales. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 892–901, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SPAR: Experience-Driven Strategy Evolution in Multi-Session B2B Sales (Zhang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.54.pdf