In this paper, we investigate the effect of listing mediation history in the context of social network service, which has been recognized as a crucial platform for word-of-mouth diffusion. We focus on how people continuously mediate a message which is previously created. Information mediation refers to active participation of relaying an inbound message to outbound subscription nodes with sending feedback signal to the original author. The behavior has contributed a lot distributing messages efficiently and effectively in SNS; whereas, our knowledge on the impact of explicit representation of mediation is limited. Moreover, listing the background information about a mediation trail may hamper readability and reduce attention to core information. Therefore, we tried to understand its impact on variation of probability by adopting duration models. Twitter was selected as a domain of interest since the site had been known for its impact of information diffusion. By investigating out-stream messages generated from hub users, we found that explicit representation of mediation history increases possibility of continuous information mediation in multi-hop context. The finding indicates that word-of-mouth diffusion in SNS can be enhanced by explicitly imparting information about a mediation trail. Our study contributes understanding the effect of using an environmental cue for persuading users to participate in information diffusion.