For the record, this show got a 5.3 rating with a 3.3 in the 18-49 range. In comparison Mad Men and Breaking Bad get around a 0.9. So yeah, this show is a hit. I'm not surprised at all because everyone loves zombies and the survival situation that goes along with it.
And to be honest, the first season is going to pale in comparison to what will be going on in the second season. Lets just say, if they plan the seasons like I think they will, the second season will be insane.