Pokemon Sun and Moon is available for digital download but Nintendo may have gone just a bit too far with it as you are going to have to go out and buy a new SD card.
Pokemon Sun and Moon is huge as each game comes in at 3.2GB and the stock card is only 4GB. So if you want to download the games you are not going to be able to fit them both on the SD card and even one is going to take up a lot of space on the card.
This means that to put Pokemon Sun and Moon on the standard SD card you are not going to have much left for anything else, so you may be better buying a new SD card for your Nintendo 3DS.
At the same time you should also be aware that if you downloaded the demo version you are not going to be able to move the data that was saved in Pokemon Sun and Moon demon to the one you purchase. This is due to the fact that the SD card doesn’t have enough room for holding both the demo and full version.
Pokemon Sun and Moon is bigger than the Pokemon Omega Ruby and Alpha Sapphire games, these were 1.8GB.
So it does look like Nintendo may have gone too far for storage as the SD card that comes with the console doesn’t offer up enough space.