Nearly half of everyone who bought a Wii U also owns a copy of the system’s marquee racing game, Mario Kart 8, according to sales information released by Nintendo this week.

Mario Kart 8 has now sold 3.49 million copies as of September 30. With Wii U hardware sales currently sitting at 7.29 million units, that’s about a 48 percent attach rate. This assumes, however, that people did not buy multiple copies of the game.

Strong sales for Mario Kart 8 are not entirely unexpected. After all, the game was adored by critics and the kart racing franchise is one of the most beloved from Nintendo of all time.

Mario Kart 8 still has a lot of work to do to catch up to its predecessor, 2008’s Mario Kart Wii, however. That game has sold more than 35 million copies.

Mario Kart 8’s release in May is just the beginning for the Wii U game. Multiple paid expansion packs are in the works. The Zelda-themed DLC Pack 1 coming in November includes three playable characters–Link, Tanooki Mario, and Cat Peach–four karts, and eight tracks. It’s priced at $8 on its own, or $12 as part of a bundle that also gets you the Animal Crossing-themed DLC pack coming next year.

For more on Mario Kart 8, check out GameSpot’s review.

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