TechCrunch reports on a new service called RapLeaf that will allow people to leave feedback to anyone that they have made a transaction with. TechCrunch thinks a third-party service like RapLeaf will be in demand because eBay's feedback system is a closed system.
eBay's feedback system is, arguably, their most valuable asset. It provides the grease necessary to make complete strangers comfortable enough to buy and sell from each other. But it's a closed system -- only eBay transactions can affect a user's feedback score. And as much as eBay doesn't like it, these users (and more) buy and sell stuff through services other than eBay all the time, online and offline. There is tremendous demand for third party services to incorporate eBay's feedback system into their applications to make them more usable. But don't expect to see eBay embrace mashups any time soon, or ever.
People will probably only leave eBay's feedback system if they are unhappy with it. They aren't going to leave it just because it is a closed system. TechCrunch also explains how RapLeaf works:
Rapleaf allows any user to leave feedback for anyone (whether they are a user or not), based on a unique email address or phone number. Type that identifier into the search bar. If no results occur, you can be the first to leave feedback for that person. This can be someone you've bought or sold with, or just a friend that you want to endorse. Like eBay, a free-text area is included for comments in addition to a positive/neutral/negative rating.
A person's feedback rating is a raw score, with a point added for a positive review and a point subtracted for a negative review (just like eBay). Non-transaction endorsements are calculated and shown separately. Various stats are calculated and displayed based on feedback ratings by others (see screen shot below).
RapLeaf is not yet live but some screenshots can be seen on the TechCrunch post. iKarma is another third-party feedback system.
TechCrunch 
