Glad this post is still up. I can absolutely put my vote behind this, and like Jen and Brian C. have said, if an off the shelf solution works, then why reinvent the wheel? Focus on the VTT and easing the learning curve for that. Of course with any rating system, there will be people that abuse it or don't provide an accurate rating. However, I think giving creators usable, constructive feedback on how to improve something makes it better for everyone involved, and in the end we all have a better experience. Maybe have some message or disclaimer saying "These reviews are for the exact product being sold here, not how the GM ran the game. These can include quality, shop responsiveness, amount of content, etc."? If someone put a lot of time and effort into a module and it was amazing, how can they stand out from someone who's product wasn't as good? I would want to support someone that made great products. I also would be much more willing to spend money in the shop if there was a rating system. It would help me have an idea of "people have generally liked this module, so it's worth picking up".