When I was saying a "trust-based system" in the original post, I was thinking about Silk Road - from what I've read from news, its eBay-like rating system repor

When I was saying a "trust-based system" in the original post, I was thinking about Silk Road - from what I've read from news, its eBay-like rating system reportedly, significantly increased the safety and efficiency of transactions overall. I was also thinking about #bitcoin-otc - the earliest Bitcoin trading community on Freenode IRC, it identifies potential buyers and sellers via OpenPGP public keys, buyers and sellers rate each other, and the bot builds a Web-of-Trust among all the participants. Alice can simply review all possible personal trust paths to Bob to assess the risk and trustworthiness. My consideration was, it has been shown some trust-based rating systems can work under the most untrustworthy environment, I just went to the assumption that a similar, elaborate design to solve problems like vendor frauds, RMA frauds, etc. So I just vaguely said "I believe having a system based on trust can be a viable solution".