New Super Mario Bros. 2 may not be regarded in the future as an iconic, unforgettable 2D Mario game — though various members of the Nintendo Life team do think it's rather good — but it did represent one important piece of Nintendo's modern history. It was the first physical retail game available to download on the 3DS, kicking off Nintendo's policy of releasing almost all — some Wii U games have gone on and off the eShop — first-party retail games on its download stores. While it can be argued that Nintendo's still catching up in some areas of online distribution and infrastructure, it bears remembering that New Super Mario Bros. 2 was only released in August 2012; since then there have been a lot of releases, some interesting promotions and general progress forward.

It's unsurprising that Nintendo's download revolution is perhaps moving forward a little quicker in Japan, where it's pressed ahead with more widespread distribution of POS (point of sale) download cards; these do have a limited presence in the West, such as at GAME stores in the UK, but they're far from being prevalent on shelves. Famitsu has, meanwhile, published an article exploring the growth of download games in Japan (translated by Siliconera); industry analyst Eiji Maeda was clear on the benefits of the products.

By placing downloadable cards on the shelves of storefronts, and using a system that provides customers with a similar sense they get from packaged software, it would eliminate the risk of retail stores having excessive stock. It’s safe to say that it’s a risk-free system for the retailers.

...Nintendo’s business style of expanding downloadable purchases, will in the long-term, prove to be a merit for the developers.

Animal Crossing: New Leaf is a title that's performed particularly well as a download, and Famitsu's poll of over 7,000 Japanese gamers showed that around 20% now opt for downloads of retail games; that's a figure that seems consistent with Nintendo's reports on download percentages.

Would purchase a physical copy—74.4%
Would purchase a digital version—20.6%
Would purchase the cheaper one—2.6%
Depends on the situation—1.4%
Depends on the title—1.0%

Nintendo still has work to do to make download purchases more attractive, of course — a genuine network account system with purchases stored in the cloud and not hardware, for example. Pricing is also an area of contention, but it seems that downloading retail games continues to be an attractive option for plenty of gamers. We'd be surprised if greater visibility of POS download code cards isn't seen in the West in 2014.