Why are people allowed to review a show before it's opened?
We understand that this is a sensitive issue. Preview performances are a special time in the evolution of the production, and criticism can really sting. In a perfect world, shows would invite audiences to attend the final rehearsals for free, in return for private feedback. That's not really practical, though, so most shows sell tickets to previews.
Because we are audience-centric, we believe that if a production is selling tickets to a preview performance, member reviews are fair game. We include the date a member review was written, and a 'during previews' label, so everyone can see whether reviews were written during the preview period, and if they change over time.
Please also remember that positive reviews during previews generate great word-of-mouth buzz that helps to accelerate ticket sales.