The article does not distinguish between the impact of reviews of plays v. musicals, but I believe that the Broadway League has published data on the question. If my memory is correct, positive reviews are far more important to the success of plays, and bad reviews of plays will basically kill them. On the other hand, word of mouth is what is critical to the success of a musical. If a musical gets very good word of mouth, it can overcome poor reviews. I guess the best example I can think of now would be Wicked.
CZJ at opening night party for A Little Night Music, Dec 13, 2009.