Super Smash Bros. Ultimate has periodically gifted paid Nintendo Switch Online subscribers with free in-game currency and Spirit Board challenges. Both Animal Crossing and Smash include added functionality that requires Nintendo's online service to access, so periodic freebies incentivize potential subscribers for whom in-game items might be the extra incentive needed for them to buy the service. Plus, New Horizons is a huge hit that Nintendo has no reason to stop supporting, so more free items are more than likely in the pipeline.