When the show is initially airing, HBO would rather you subscribe to the cable channel, since the cable company pays them much more than Netflix or Hulu would.

When the season ends, HBO would rather you buy the DVD / Bluray, since the sale of those discs pays them much more than Netflix or Hulu would.

It's certainly possible that one of the digital vendors could offer HBO enough money to change their mind there, but it's a fairly daunting check to write.

Why would HBO license their content to Netflix or Hulu for a pittance when they could make more money offering it directly?

HBO has already stated that the only thing holding back HBO Go is that its current contracts with cable and satellite providers are still too profitable to cannabalize with a dedicated online offering (and more to the point, are effectively cost-free since HBO does not have to employ a sales/marketing force).

I see. What an endless chain. Consumers can't switch out of cable because they want to watch GoT. HBO makes sure that you can watch only on cable because they make so much money out of it. We consumers pay way too much to cable operators to get so little out of it.

I think the problem is sports. If sports could move to online streaming, then the entire cable industry would crumble.