现有研究主要考察了不同卖家在同一平台型电商存在的绩效差异（平台内差异）。而对于同一卖家在不同平台型电商存在的绩效差异（平台间差异），却少有人关注。为此，本文基于声誉理论，通过三项研究探索了平台型电商声誉对卖家绩效的影响效应与作用机制，试图据此解构卖家绩效的平台间差异。研究结果表明：（1）平台型电商声誉对商品销量具有显著的正向影响，但对商品价格的影响效应却不显著。不仅如此，平台型电商声誉对商品销量的影响主要通过锁定效应和信号效应来起作用，尤其是对冷门商品（较之热门商品）的影响更加显著。（2）平台型电商声誉的锁定效应主要体现在其完全通过商品多样性和卖家专业性对平台忠诚产生正向影响。并且，买家购物经验越多，卖家专业性在平台型电商声誉和平台忠诚之间的中介作用越大。但是，买家购物经验对商品多样性在平台型电商声誉和平台忠诚之间的中介效应却不具备调节作用。（3）平台型电商声誉的信号效应主要体现在其完全通过商品感知质量对商品购买意向产生正向影响。对于搜索品来说，商品感知质量在平台型电商声誉和商品购买意向之间的中介作用较为显著；对于体验品来说，商品感知质量在平台型电商声誉和商品购买意向之间的中介作用却不显著。

Existing research mainly examines the differences in performances of different stores, affiliated to different sellers and from the same e-commerce platform, which is defined as seller performance difference within e-commerce platform. However, few scholars pay attention to the differences in performances of different stores, affiliated to the same seller and from different e-commerce platforms, which is defined as seller performance difference between e-commerce platforms. Hence, this paper explores the effect and mechanism of e-commerce platform reputation on seller performance via three studies on the basis of reputation theory, in order to find an explanation to the seller's performance differences on different e-commerce platforms.The findings indicate that e-commerce platform reputation has a significantly positive effect on sales, but has no significant effect on price.Moreover, e-commerce platform reputation affects sales primarily through lock-in effect and signaling effect, and the impact is more beneficial when the product is an unpopular product than when it is a popular product. The lock-in effect of e-commerce platform reputation is mainly demoristrcfed by the fact that e-commerce platform reputation has a positive effect on buyers' loyalty to the e-commerce platform exclusively through product variety and seller expertise. In addition, the more experienes the buyers have in transactions on e-commerce platform, the stronger the seller expertise plays intermediary role to e-commerce platform reputation and buyers' loyalty to the e-commerce platform, but buyers’ experience has no moderating effect on the mediating role of product variety. The signaling effect of e-commerce platform reputation is mainly demonstrated by the fact that e-commerce platform reputation has a positive effect on purchase intention exclusively through perceived product quality. Furthermore, the mediating effect of perceived quality is significant for search products, while not significant for experience products.