I'd also like to see a feature where established customers ($x bought over y time) can flag an entry as suspect--an entry gets enough flags and a human looks at it. If the entry turns out to be suspect everyone who flagged it gets a bit more flagging reputation, if it's wrong they get a bit less. The more flagging reputation you have the more your flag counts towards getting a human to investigate.
Disagree. They should do what Apple does for App Store reviews. Reviews of the latest version only, with other reviews as “background” data.
It's more the other way around. Initially you could only sell something on marketplace if it was something Amazon already listed, usually a book. There would be an option on the Amazon listing to buy it elsewhere and if you selected that there would be a list of non-Amazon sellers you could buy the book from - these would normally be individuals reselling books they had finished reading.
And then they added a feature where if multiple marketplace vendors are selling the same thing it combines them.
And a third feature lets you classify items as various colors of a product (but the same product - think blue vs pink socks) and all the reviews get combined.
So if you do all three in the right order you can change anything to anything now, even taking another listing.