The show being on Netflix and Hulu might help it since it'll give people a chance to catch up. Like Hunter Rider said, this show moves pretty quickly, which is great, but it makes it difficult for new AND returning viewers. For example, last year, I remember many people complaining during the season's first-half when Alex was a trainee at Division. Many of them stopped watching. If those folks decide to come back, they'll be completely lost. This show has only aired 28 episodes, and yet, it feels like 48.
I don't expect the show's ratings to rise over-night because it isn't the type of show that people can jump right into. The best bet is the holiday hiatus. The show has been on Netflix (and soon Hulu) for a week or two now. Hopefully, people are checking it out. Then, in December, they can catch up with season two's first half.
CW will wait till January/February to evaluate the show's success.