Yo. In case this hasn't been posted...
How To Merge Nintendo Switch, 3DS, And Wii U EShop Credit
Yes, they're separate, but you can change that.
Nintendo Switch's eShop, which launched via a day one update, has separate account balances to its 3DS and Wii U equivalents. That means if you have unspent credit sitting in your 3DS or Wii U wallet, you can't spend that without first merging that wallet with the new Switch system, called a Nintendo Account.
Luckily, doing so is easy. Simply go to your Nintendo Account page, and choose to merge the two wallets so you can spend previously redeemed vouchers on games for Switch.
Nintendo Switch also allows you to access other regions' eShops. Find out how to do so here.
Nintendo Account is the new replacement for Nintendo Network, while the former is also tied to My Nintendo, the rewards service similar to the now-defunct Club Nintendo. You can link your My Nintendo and your Nintendo Account here.
Nintendo Account also allows you to pick a new user ID, similar to PSN's naming system or Xbox Live's Gamertags. You can't currently add friends using your user ID--friend codes are the primary way of doing so right now--though more methods of registering new pals are on the way.
Many questions remain about elements of Switch's online service, including how its mobile app will work, when Virtual Console will debut, and exactly how much its premium online service will cost.
Nintendo Switch is out now. If you have a last-minute desire to purchase one, check out our post on how to buy one at launch (possibly).
For more on the Nintendo Switch, check out GameSpot's roundup of everything you need to know.
http://www.gamespot.com/articles/how-to-merge-nintendo-switch-3ds-and-wii-u-eshop-c/1100-6448397/
