It is a new game for Nintendo fans. And a 16GB cart is more expensive than a 50GB blu-ray disc. This game use 32GB cart
Memory prices have crashed down so much lately that I expect the price difference between a Blu-ray disc and a 16GB cartridge to be negligible by now, and the 32GB cartridge not much more expensive anymore. In fact, if the prices keep dropping as much as they did the last 2 years, then by 2022-2023 50GB Blu-ray discs will have to compete in price with 64GB cartridges. And this will probably be the point at which optical drives will go the way of the Dodo, safe for consoles, possibly movies/TV shows and some special uses, like archiving.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454