Nintendo Switch had a stellar first year, and three major game releases were the biggest drivers of that success. The Legend of Zelda: Breath of the Wild helped Switch to a strong debut, Mario Kart 8 Deluxe (despite being an enhanced port) had a phenomenal launch a month later, and Super Mario Odyssey was a massive seller during the holiday 2017 season.
A year later, these three games are still selling well, helping Switch achieve yet another sales record. Speaking with IGN, Nintendo of America President Reggie Fils-Aime revealed that all three titles are owned by over 50% of Switch players in the United States. It's common to see high attach rates for hit games on a brand new console, but typically that percentage drops over time.
"Those three games continue to attach to hardware at better than 50 percent. Just think about that. For everyone who owns a system, more than one out of every two have bought Zelda, more than one out of every two have bought Kart, more than one out of every two have bought Odyssey. That's never happened in U.S. video game history." — Reggie Fils-Aime
Those three mega-hits have each sold over 10 million copies just on Switch, and two of them have also sold millions more copies on Wii U. A 50% attach rate is nearly impossible to maintain for a console's entire life cycle, but all three titles are "evergreens" that continue to sell well as new customers join the Switch family.