The Wii U sold just 46,000 hardware units in January at brick and mortar locations — a shockingly low number for a console that was just released in late November. To put it in perspective, the Wii sold 348,000 units during that system's comparable period in 2007.
Officially, according to NPD data, Nintendo has sold 57,000 Wii U units this year. The adjusted figure of 46,000 is a more accurate comparison to the 2007 figures, though, due to reporting calendar irregularities. (January's NPD results are a skewed due to the addition of a "leap week" the group has to add every five or six years to balance its reporting periods. NPD measures the year into 12 reporting periods of four or five weeks. That results in some date discrepancies, which require the leap week to be added occasionally.)