The purpose of this study is to find out what factors affect the conversion rate on e- marketplace sites in Indonesia. It can serve as an input for sellers to formulate the right strategy for them to increase the conversion rate, as well as provide inputs to e-marketplace managers in Indonesia in developing new features to improve conversion rates on their websites. This is necessary because these features are one of the main revenue from managing e-marketplace services. This research uses big data analytics methods, this research uses causal research method to give detail explanation about causal relationship between variables. The end result of this research is to find out whether factors such as signaling methods, transaction success rate, and price promotion have a positive effect in increasing the percentage conversion rate of an e-marketplace site.