Twitch Prime subscribers can currently get 12 months of Nintendo Switch online for free, just by heading to this website, logging in with your Twitch account and then connecting it to your Nintendo Online account.
It’s important to note that if you’re an Amazon Prime subscriber ($5.99 a month), you also get access to Twitch Prime, so this makes you eligible.
You’ll get three months of Nintendo Switch Switch online up front and then the other nine months 60 days after claiming your first three months (this is so you don’t just subscribe to one month of Prime then unsubscribe).
It’s a pretty good deal. I was already signed up for Amazon Prime, which mean that I was able to add to my Nintendo Switch online subscription for free.