To be honest, I’m mostly interested in Hayao Miyazaki’s films (My Neighbor Totoro, Princess Mononoke, Ponyo). They aren’t available on Netflix, iTunes, the PS3 or Xbox VOD services despite other Disney-owned movies (Pixar movies for example) being available there. Has Disney ever put any of Ghibli's films in any digital distribution service?
For whatever reason, Disney seems to prefer more traditional distribution methods. Going to Disney's Studio Ghibli page, I could not find any information on purchasing these in any digital format. All of the links they had were to purchase physical DVDs or Blu-rays. If they were selling it in a digital format officially, I imagine they would have included that on the website.
As for streaming services, you've listed most of the relevant ones, which probably means it isn't being streamed anywhere legally. I know for a fact that Ponyo was available at one point for streaming through Netflix, but what movies these services offer can vary on a day-to-day basis. I can't tell if any of them are available for streaming at the moment, but even if they are, it would likely change in the near future anyway, so your best bet is just to check with whatever services you do use and see if they have it. If not, your only legal option (at the moment) is to buy the DVD/Blu-ray.
I have discovered that its the 'Japanese arm of studio Ghibli' that is withholding the digit oral distribution rights and bans any company or studio from selling or renting the Ghibli films in digital format. But what they gain by doing that is a still anyone's guess. :-/
Truthfully no one knows why they won't release the films digitally. I've had no luck in trying to contact Ghibli, Disney who do the American dubbing and distribution, or StudioCanal who now do the UK distribution.
The simple answer is you can't buy them anywhere and the only way to get hold of them is to rip a digital file from the DVD or Bluray, if you have the know how to do that, or get the films illegally from Internet torrents which no one wants to do as a general rule, given that its fiddly, time consuming, unreliable and illegal. Presumably, there's some complicated licensing issue at stake or perhaps one of the investors has some vested interest in Bluray or DVD distribution that they need to protect, but it's all guesswork and conjecture unless someone can find an explanation or actually get a response from one of the companies on the matter.
I'm just a Miyazaki fan like any other and am always frustrated by this when I periodically try and hunt for any of the films to buy so I message them on their UK Facebook page intermittently to try and get their attention on the matter, though again I've never had a personal reply to any message I've sent, nor to any queries I've sent directly to the studios. But I did start a petition the other day on change.org and sent it out into the net just to see how much attention it gets as I'd be curious to know if there's many other people looking for these films online or if I'm just a frustrated minority.
The petition is connected to Disney and StudioCanal who seem, according to Google searches, to be the studios currently controlling the western distribution rights. Whether there are other companies imposing the restrictions from elsewhere, it's hard to tell but Disney and StudioCanal are the ones losing profits by not selling the films and so if enough people post on their Facebook page, email other studios and sign petitions like the one I've started, then eventually the studios might start thinking there's enough interest in the films that its worth resolving whatever issues are preventing their digital distribution and releasing them. They're the ones who have the power to change things and resolve whatever problems are holding the films back so if they can be made to see they are encouraging piracy of films they hold the rights to by refusing to sell them and thus losing out on millions in revenue from those lost sales then logic would suggest that eventually they've got to see reason and fight whatever is preventing them from releasing these films. Holding them back must be losing them money from lost sales and encouraging piracy to boot as that's the only way to get the films at the minute so presumably there must be a huge legal, financial or contractual obstruction in the way that is preventing the films being distributed and knowing exactly which studio or company is responsible for the restriction is nearly impossible but with enough consumer interest and consumer complaints they must eventually relent and resolve the issue.
For now the only solution to this problem, apart from reverting to DVDs and Blurays, seems to be pirating the films illegally (far from ideal or advisable for many obvious reasons but as absurd as it may seem that is the only option people are being offered currently) or alternatively the only other option is contacting and pleading 'en mass' with the studios involved to request the release of the film. My humble attempt to write a petition is below and states the frustration of not being allowed to legally buy films and being forced to pirate or go without and the logic of releasing the films digitally and pleads with the studios to release them.
Anyone out there who wants to see these films released, I'd encourage you to consider signing it or even starting your own petition if you believe you have found a better platform to launch one from or a more direct line to the correct studio or person that hold the decision on releasing these films or not. But also reply on this post or others if you find out any further information on why the films aren't available or who is responsible for their restriction.
The best educated guess is what's already been stated in previous answers, that the studios (Disney and StudioCanal it seems but there may be other Japanese studios in loved in the matter too) may (and this is purely guesswork) have a financial investment in Bluray or DVD so don't want to support the (perhaps less profitable?) digital distribution of the films. If this is the case then the way to reverse their decision would be to convince them that they have more to lose by not selling the films digitally than to gain by only selling physical discs.
If they think people are buying the discs because they're not sold digitally then they will never release the films but if they get the message that people are choosing to pirate the films instead of buying he discs then they might realise that it's in their interest to sell the films online digitally. A popular misconception is that video piracy exists because people don't want to pay but the emergence of iTunes and Netflix, et al has shown a huge drop in piracy, suggesting that people are quite happy to pay if the price is right and the service is easy to use so far from piracy being held in place by copy protection and legislation it would seem its actually prevented by offering consumers an easy affordable alternative.
That is the message that the studios need to hear from their customers in order to convince them that wide digital distribution of films is the only solution to preventing piracy. For the moment they may still see Blurays and DVDs as more profitable but until the scales tip completely over to digital streaming sales the only way to make your voice heard is to speak up to the studios. If enough voices are heard they will listen. They have no way if knowing how many people are refusing to buy physical discs or have already bought discs but would be willing to buy digital versions too if only they were available so the only way of them knowing that is if consumers speak up. This isn't an answer to where you can buy the films in the short term but hopefully it may be part of the solution to ensuring people can buy the films in the long run.
If you live in Italy, since the 8 November plenty of Studio Ghibli features are available on Infinity, the new streaming service from Mr. Berlusconi's Mediaset:
As I live in the UK, I cannot subscribe that service, but apparently they may even allow you to download the features on mobile devices.
The Infinity TV blog dedicated a recent entry to Miyazaki:
If Studio Ghibli allows that in Italy, I would imagine is merely a matter of providers for other territories not being able to match its commercial demands.
While anime in Italy is not as big as in Japan, it is way bigger and popular among the general audience than in USA or in UK, so new challengers on the digital market arena such as Infinity TV are probably getting a larger incentive on matching the requests of the Japanese film studio or of its distributors.