The point is though, even if they put the past seasons of those 5 shows on the service, Netflix also still has them. And even if the deal they signed with Netflix for some reason expires that fast (which I doubt), there's no way new episodes will be premiering on the service over continuing to air on the CW.
So what's the incentive to sign up for the service? For new shows, it's pretty slim. Instead it seems to primarily be the back catalog.
I agree that the service will be lacking for most people. I think many of these services have the most appeal to cord cutters, but this is such a niche offering that their target market will be very small.
Disney, for example, toyed with the idea of separate Star Wars or Marvel services, but decided that they'd be stronger to have a single service that brought in a much greater amount of content. That's the smarter play, I think.
I just don't see how this DC digital service has much appeal compared with Netflix, Amazon Prime, Disney's, Hulu, HBO Go, or even CBS. Perhaps making it lower cost ($4 per month rather than $8-10) might work, but Time Warner has so much content that it seems like it could have made a service that would compete with the others, rather than this minor niche offering.