@k_thor: I guess because not a lot of people over here are talking about Vikings, but 3.5 million is not bad for the network its on. I am pretty sure that show is on a subscription channel.
The CW is still a network channel, but viewership wise you can compare it to a cable network. The CW was created around 2006. It is a merger of The WB and UPN. You technically do not have to pay for the CW.
@k_thor: The Cw is considered like a cable channel in viewer regards. Example: Teen Wolf is widely popular, but only brings in maybe 2.0 millions views. Cable and Network ratings are very different. Same for some award winning shows. Homeland only gets 1 to 2 million views, but it is a widely successful television show.
Not all networks play that way. The CW still has Beauty and the Beast on just because of their strong fan base. Their numbers are horrible. Less than a million views for some episodes.
Movies and Television are different. Box office numbers matter a lot more for Movies and that is why fan bases are less powerful for film. Look a t Kick Ass same example. Low numbers but a cult following.