Grimm finally premiered on Friday, October 28th. According to TVbytheNumbers.com the first episode got a 2.1 rating for adults 18-49. This is pretty good considering that the show was up against the World Series. Sadly, the ratings dropped down to a 1.8 for the second episode. It's still a good rating considering that it is one of the highest rated shows on Friday night. I don't think that NBC was expecting it to get as high of a rating as it did because they decided to schedule it at 10pm on Friday and started airing it mid season.
Personally I really love the show. I think it's a very creative idea and I thought it was cool how the first episode was based on the little red riding hood story. I can't wait to see the rest of the series. :)