The Wii U has undersold but out-earned its predecessor in its first full month on the market, according to new data from the NPD Group.

In its first 41 days on the market, the Wii earned Nintendo US$270 million, with around 600,000 units sold in its first eight days.

Over that same 41 day period, 890,000 Wii U’s have been sold, but its higher asking price has netted Nintendo more than US$300 million.

In addition, more than 580,000 copies of New Super Mario Bros. U have been sold.

"While the Wii launch established new benchmarks in the United States, Wii U has surpassed its predecessor in perhaps the most important category: revenue generation," said Nintendo executive vice president of sales & marketing Scott Moffitt.

Nintendo is hoping to sell 5.5 million Wii U consoles by the end of March.