For Etsy's first four years, buying an item and sending payment were two separate actions. Payment was sent via PayPal after completing the checkout process on Etsy.
Because of this, it was important for buyers to have public feedback. It was how sellers would gauge the trustworthiness of their buyer, and it was a strong incentive for buyers to send prompt payment.
In November of last year, building atop PayPal's new Express Checkout, we changed the way checkout works. We now require that payment be sent before the purchase can be completed.
This means that the buyer's primary responsibility (making the payment) is now taken care of up front. As such, it is now much less important for a buyer's feedback to be public.
People have often asked for the ability to make some of their purchases private, and this feature is on our product roadmap. In the meantime, we're making the feedback that sellers leave for buyers private. We're also removing the link to the item for feedback that buyers leave for sellers.
The feedback score itself is still public, and will remain so.
This change is also reflected in our API. This data is no longer publicly available.
We strongly believe in the value of public discussion around a purchase. We have plans for making this discussion more meaningful, and will continue to improve the feedback system.