I think good review and ratings systems for online marketplaces are possibly one of the hardest things to get right. I'm not sure it's ever been done really well before, or even if it can be done well. As a spouse of someone with a successful Etsy shop, let me tell you that the sellers aren't always exactly happy with the system either.

You have to basically keep it at perfect feedback in some goods marketplaces or you're considered a fuckup, and while that's easier than it sounds because people don't know how to rate effectively so almost all feedback is perfect, you also have to deal with people that leave negative feedback because of issues that have nothing to do with what they ordered (tracking shows USPS lost he package for a week or two in delivery, or shows it delivered to correct address but customer did not receive it).