Social network services (SNS) have been used to support sellers in e-commerce marketplaces for years. It offers multiple affordances to sellers to promote their products, maintain relationships with customers and learn from other sellers. However, the open nature of online SNS also fosters competition as sellers can closely follow each other. How SNS impacts the sales performance of online sellers has not been studied in the literature. This research presents a preliminary study to explore the role of SNS on the performance of online sellers, with a focus on seller’s network prominence in SNS. Four types of network prominences are proposed in the research and data from 83,462 stores were collected over two years to empirically verify our hypotheses.