Review system equivalent to Amazon Review or similar.

For those promising content in the form of an unlock-able purchase, we should have a review system in place. Upon completion of a sale, Rarible can prompt the buyer to include a review of the purchase (score of 1 - 5; if 1 where is bad and 5 is best), and an option to include a written message. If the buyer completes the review, Seller can opt to publicly display the review.

This would add value to the individual account holder, naturally incentivizing a positively reviewed account, with the benefit of trust.