Is Mario Kart Currently Nintendo's Biggest Franchise?

[IsawYoshi]

newwil7l said:

NintendoPie said:
The Wii Series is, I think, the best selling Nintendo series of last gen... I think.
But Mario Kart is growing quite fast and gaining quite a large following. It's really packed on those sales as of late.

Well we all know the Wii series has lost a ton of popularity

How? The wii u haven't gotten a game in the wii series.