Nintendo is currently running a “limited time” promotion where you can earn 1,000 I Nintendo Gold Points when you purchase or renew a 12-month family membership for NSO or the Expansion Pack service.
This offer is currently open to North American residents and will be available until August 11, 2024. These gold points can be replacement for games on the eShop and other Nintendo Switch content.
Switch Online gives you access to online play, classic games, cloud storage services, a smartphone app and some special offers. The Expansion Pack service comes with extras like DLC and more retro services.