As global e-commerce platforms continue to expand, companies are entering new markets where they encounter cold-start challenges due to limited human labels and user behaviors. In this paper, we share our experiences in Coupang to provide a competitive cold-start performance of relevance matching for emerging e-commerce markets. Specifically, we present a Cold-Start Relevance Matching (CSRM) framework, utilizing a multilingual Large Language Model (LLM) to address three challenges: (1) activating cross-lingual transfer learning abilities of LLMs through machine translation tasks; (2) enhancing query understanding and incorporating e-commerce knowledge by retrieval-based query augmentation; (3) mitigating the impact of training label errors through a multi-round self-distillation training strategy. Our experiments demonstrate the effectiveness of CSRM-LLM and the proposed techniques, resulting in successful real-world deployment and significant online gains, with a 45.8% reduction in defect ratio and a 0.866% uplift in session purchase rate.

Business-to-business (B2B) e-marketplaces serve local small and medium-sized enterprises (SMEs) by assisting them in connecting with potential overseas buyers. They leverage multiple channels to connect with and bring potential leads to SMEs. The authors' understanding of such an intermediary has been either largely impaired by limited studies on the services that e-marketplaces should offer or implicitly deduced from business-to-consumer studies. In this work, the authors attempt to unveil whether the efforts that an e-marketplace has made are associated with the continuance of its SME clients. To answer this research question, a set of data from a B2B e-marketplace connecting qualified SMEs with overseas buyers was used for analysis, and they discovered three results. First, generating many online leads is negatively associated with SMEs' continuance with such an e-marketplace company. Second, organizing many online videoconferencing meetings between SMEs and buyers can promote this tendency, which is different from organizing many offline meetings. Third, onsite visits that e-marketplace salespersons make can attenuate the negative effect of the generation of online leads. Their follow-up interviews unveiled that SMEs only desire sufficient attention to obtain tangible results from a B2B e-marketplace.