The service that Netflix offers is much more convenient than traditional cable television channels. A customer of Netflix can watch, on demand, almost every show they might possibly want. Not to mention that these shows are ad-free as well. Where HBO is ad-free, it costs a premium subscription and does not contain the capability of watching, on demand, any television show that the viewer may want.
Netflix specifically is not the future of TV, I don't believe, but the internet itself is the future of TV. People want to watch what they want to watch and they want to be able to watch it anywhere. With services like Hulu and Netflix, you can watch TV on your phone, your laptop, your television, etc.
It's inevitable that Netflix and similar companies will be taking over the future of TV because they can offer services and products more quickly, and "quickly" seems to be the main priority of consumers these days. There is a definite direction being drawn by consumer usage, and it appears that this is the future of TV.
I think that many will agree with me that the days of renting a movie at the brick and mortar retail stores are gone forever. It makes much more since to most Americans to buy a subscription like Netflix online and stream movies; however, I still think there will always be a market for companies like Redbox. These companies will target consumers that want a short-term commitment over ease of access. There will always be people, including myself, that feel it is more economical to just rent one or two Redbox movies a month.