Mario Kart 8 may have been the Wii U’s savior as the game helped sales big time.
Nintendo of America president and COO Reggie Fils-Aime mentioned to Polygon:
Sales of the Wii U console quadrupled the week after the release of Mario Kart 8, compared to the week prior
It was mentioned a few weeks ago that Wii U sales over in the UK increased by an amazing 666% following the release of Mario Kart 8. The game already sold over 1 million copies in its first weekend.
With loads of new games announced for the console at E3, Nintendo might see more spikes in hardware sales in the near future.