We already know that Mario Kart 8 enjoyed a terrific launch, confirmed to have sold 1.2 million copies in its opening weekend and to have boosted hardware sales in UK. It's a vital first step in driving Wii U sales in 2014, and it seems those positive headlines also equate to some impressive results in the latest NPD results for May, which account for physical retail sales in the US.
Overall a number of new releases drove physical software sales to a 57% increase over May 2013, with the hardware number increasing by 95%.
As you can see in the top 10 software sales below, Nintendo's kart racer is only behind Ubisoft's multi-platform title Watch Dogs.
Kirby: Triple Deluxe can also boast a positive result as a single-platform title, launched on 2nd May and securing ninth place; Mario Kart 8 had just its opening weekend to claim second place.
Overall, Sony's PS4 was the top-selling hardware, though we're awaiting firm sources to confirm Nintendo's performance in this area — there are suggestions that 3DS was in second place, though the only figures currently available are unofficial. NPD analyst Liam Callahan has also said that while "much of May 2014's hardware growth was due to Xbox One and PS4, there was also year-over-year growth for the Wii U, and PS Vita"; that reinforces often repeated comments from Nintendo of America President Reggie Fils-Aime, during E3, that Mario Kart 8's release prompted a 4x increase in Wii U hardware sales.
These are certainly positive results for Nintendo, while it'll be interesting to see how momentum for its games and systems hold in June.