Ring Fit is a Blue Ocean title.  Blue Ocean titles reach a new group of customers.  

When you sell to an already established group then you get a huge spike of sales at launch and then it drops off quickly.  The customers are already there.  Blue Ocean titles sell to customers that wouldn't have otherwise bought the system (as you have pointed out, this is a game people would buy a console for).  They aren't even customers that would normally even keep up with gaming in the slightest.  So they buy the game steadily over time.

Damn, Ring Fit looks like its gonna be a sleeper monster. Forgettable launch but super legs. Looking forward to see its worldwide total for 2019.

The ocean is growing, RFA and to a lesser degree Grain Training are attracting additional players to the system.

And I'm all for it, as PS5 vs XSX looks like it's gonna be same old, same old, just with MORE! POWER! That won't attract new customers.

Pretty good result for Yakuza 7 with 75% second week drop compared with 80% for Y6. I read that Y7 is on 300k shipped + digital so hopefully, it might be able to outsell Y6's ~400k LT, and reverse the long-running decline.

I am not completely sure about that...Well this is only the words on 1 person. Then under it you have my bullish comment.

Ring fit is a monster! Who knew fitness games can still sell that much at this generation!

"Lucky to hit 5m"

"The Wii Fit cazualz are all on smartphones"

Switch and the Nintendo Ring have been sold out since Christmas and are still supply constrained in UK.

Japanese shipments+digital (December 31st 2019)

Super Smash Bros. Ultimate - 4.220.000
Pokemon Sword / Shield - 4.210.000
Splatoon 2 - 3.780.000
Mario Kart 8 DX - 3.250.000
Super Mario Odyssey - 2.410.000
Pokemon Let’s Go Pikachu! / Eevee! - 2.050.000
The Legend of Zelda: Breath of the Wild - 1.910.000
Super Mario Party - 1.680.000
Super Mario Maker 2 - 1.120.000
New Super Mario Bros. U DX - 950.000
Luigi’s Mansion 3 - 730.000
Ring Fit Adventure - 630.000
Fire Emblem: Three Houses - 530.000
The Legend of Zelda: Link’s Awakening - 420.000
Astral Chain - 160.000
Marvel Ultimate Alliance 3: The Black Order - 40.000

Week 2, 2020
Top 20 SW TOTAL: 229.422

Week 3, 2020
Top 20 SW TOTAL: 225.288

Week 4, 2020
Top 20 SW TOTAL: 175.400

Top 5
1) Ring Fit Adventure - 39.217(+9%)
2) Pokemon Sword / Shield - 37.950(-32%)
3) Dr. Kawashima's Brain Training for Nintendo Switch - 12.875(-18%)
4) Minecraft - 10.827(-22%)
5) Super Smash Bros. Ultimate - 9.927(-20%)

Week 4, 2019
Top 20 SW TOTAL: +170.112

TOP 5:
1) New Super Mario Bros. U Deluxe - 56.465(-40%)
2) Super Smash Bros. Ultimate - 37.015(-20%)
3) Super Mario Party - 12.525(-30%)
4) Mario Kart 8 Deluxe - 10.670(-37%)
5) Pokemon: Let's Go, Pikachu! / Let's Go, Eevee! - 10.122(-17%)

Week 5, 2019
Top 20 SW TOTAL: 175.646+

TOP 5:
1) New Super Mario Bros. U Deluxe - 45.030(-20%)
2) Super Smash Bros. Ultimate - 33.170(-10%)
3) Pokemon: Let's Go, Pikachu! / Let's Go, Eevee! - 17.312(+95%)
4) Mario Kart 8 Deluxe - 12.465(+17%)
5) Super Mario Party - 11.725(-6%)

+ Top 20 Switch games were outside the Famitsu Top 30 numbers

• As expected, Software slightly up this year compared to last. Next week will be tougher to beat since Pokemon Lets Go Bundles drove up Software sales a bit last year. 
• Ring Fit Adventure was outlined as a hardware mover during the financial brief, so it's supply will determine both hardware and software trajectory in the coming weeks for the Switch. 
• Animal Crossing Bundle might have a negative impact on hardware sales, but we will see it's effects in the coming weeks. Currently hardware trajectory is looking good. 
• No new releases that could break 50K until Hatsune Miku: Project DIVA Mega Mix, which should be helped by it's vicinity to Animal Crossing's launch and the new demographics buying the Switch for Ring Fit/Animal Crossing. Wont' be surprised if this game is the best performing Miku game since 2014. Back than Hatsune Miku: Project Diva F 2nd sold well over 100K on the Vita. 

Too bad Ultimate Alliance 3 didn't do well there.  Solid game.  At least it hit a million world wide.