Another issue might be, how do you deal with people selling illegal items/services? How do you avoid “Silk Road” style liability? Would there be a blacklist that someone running an instance could use so they don’t have to vet everyone they are federated with?
I wonder if you can ‘outsource’ trust by relying on payment systems? If a seller uses stripe and scams some users, stripe would freeze their account right?
I really like the idea of a grassroots Amazon competitor. That said,
You need to have a high level of trust. A federated network of shady scams that just take your money and send you nothing half the time is not going to fly. Is there a vetting process, who controls that process, how’s all that work. If its ‘good seller’ reviews, how are those stats protected from manipulation.
You need to have extreme ease of use. UI barriers that seem trivial to developers can sink a platform.
If there are problems solvable by centralization, maybe that could be done as a cooperative organization which devs and vendors can join and run democratically.
I order stuff from ebay. Got a phone on the way from china right now. Ebay work-alike might not be a bad place to start.