Those are some interesting ideas for escrow services, summer. There are trade offs. In the first example, Bob loses 1 BTC even though Alice breaks even on the scam, so a malicious person could scam just to hurt other people, at no personal benefit. On the other hand, people could elect to use such an escrow service because it never finds out their transaction details. The great thing about a decentralized market is that all of these escrow services could exist. People could choose which ones they want to use. Seller's could include in their product listings the types of escrow services they are willing to use. A trusted escrow provider could offer different types of escrow: a "traditional" service where live humans get info and evaluate the situation, and various automated and blind services, perhaps at different percentage rates. Let a thousand flowers bloom. This is how innovation happens, when you escape the grip of central control.