Amazon.com has opened their new Nintendo Digital Downloads Page. It already as a fairly extensive collection of games available for both the Nintendo 3DS and the Wii U, including the soon to launch Super Mario Maker. This also includes a number of Virtual Console games as well. You can search specifically for only Wii U games or only 3DS games, or search by other criteria. The selection of games contains mostly first-party Nintendo titles such as Super Smash Bros., Mario Kart 8, Hyrule Warriors, and Splatoon among many others.
As you browse this page, you will likely end up on the individual pages for various games. For games that are available on physical media like Wii U game discs or 3DS game cartridges, you have the option to order a physical copy of the game, or instead order a digital download code that will allow you to download the game in question from the Nintendo eShop (on the appropriate Nintendo system of course). Amazon’s Nintendo Digital Downloads page may not be as extensive as the Nintendo eShop itself, but it still has a fairly extensive selection of games available to browse already, and it will probably expand over time. Some games are cheaper if you get them digitally, while others may be the other way around. So you’ll want to pay attention to those prices as you browse the available games.
So in short, you can do your Nintendo eShop shopping on Amazon.com now if you already do a lot of shopping on their site. Just remember that for now it is mostly populated with first-party Nintendo games so you might have trouble finding third party titles on it for the time being. This will likely change over time as Amazon’s Nintendo Digital Downloads hub expands, though.