Consumers have collected information and sought advices from other consumer through Internet. They could collect information in virtual space (online) not real world that is Electronic Word of Mouth (eWOM). This study focused on research the factors on effect in Electronic Word-of-Mouth (eWOM) in the open market which is mediate between individuals and online stores. This is an exploratory study for research on finding factors of effect in eWOM. First of all, 5factors are selected from interview with 31 consumers. Then online surveys are conducted and 5 factors are significantly supported. This study is academically new approach on an exploratory study and it could suggest marketers to strategically manage eWOM.