Giggs_11 on 03 June 2015
If I'm not mistaken MK was selling around 4/5k a week for quite some time and now it more than doubled to 11/12k. So a lot of those 17k who bought WiiUs for Splatoon also bought Mario Kart, which means some people were waiting for Splatoon to get a WiiU along with other games such as MK.
Splatoon system seller confimed!
On a more serious tone, Mario Kart just broke 1 million after 1 year ont the market. That's great for a home console over there. Also great Withcr 3 second week sales. It desserves good sales.