Nintendo managed to sell 3 million Wii U consoles worldwide during the final nine months of 2014, marking only a slight increase from the 2.4 million sold in the same period of 2013.The new figures bring the Wii U's total lifetime sales to 9.2 million, an indication that, despite key releases such as Mario Kart 8 and Super Smash Bros for Wii U, Nintendo is still struggling to push forward with its troubled system.By comparison, the original Wii had surpassed 44 million sales worldwide after its third Christmas on the market.