My Nintendo coins can help you buy Nintendo Switch Online
https://www.polygon.com/2018/9/17/17870186/nintendo-switch-online-price-my-nintendo-gold-coins
Anyone who’s managed to stockpile My Nintendo gold coins, the members-only point system awarded to Nintendo Switch owners for buying games, has a new thing to spend them on. Once Nintendo Switch Online launches Tuesday, Sept. 18, My Nintendo members can put some of their gold coins toward the cost of their subscription to the service.
On Nintendo’s support page for Nintendo Switch Online, the company explains how users can redeem gold points toward a subscription.