What does Nintendo need to establish a good subscription system?

[Darwinianevolution]

With the DeNA deals that Nintendo has made, one of the things people is waiting for is an account based system for the growing digital sales, allowing people to tie their games on an account instead of them being limited to a piece of hardware. I also think that, with this account system will come a subscription program similar to PS+ or XBox Live.What does Nintendo need to establish a good subscription system, and make it succesfull? Also, what does Nintendo need to avoid to not anger the not-subscription users (ehem not putting online multiplayer behind a paywall ehem)?