Can I subscribe to HBO Now through my cable, satellite or internet provider?
The great thing about HBO's new streaming service, HBO Now, is that it allows you to access the network's full content without having a cable or satellite subscription. You will, of course, still need broadband. Apple and HBO currently have a three month exclusive partnership so, at launch, you can subscribe either through iTunes or the HBO Now site, or download the app to your iOS device or Apple TV.
If you are hoping to cancel your HBO cable subscription and subscribe to HBO Now, but keep your other cable channels, it's not clear if or how that will work, as most providers bundle HBO in a package that includes other channels. There is a chance that could change though - according to HBO's FAQ, the network is in "discussions with [its] existing network of distributors that sell broadband and [hopes] to announce such relationships soon." It would at the very earliest be three months after launch though.