The NPD Group has released its U.S. video game retail estimates for January 2013, but they require a little bit of explanation. The NPD's reporting schedule aligns with the National Retail Federation's, including its "leap week", which happened to fall on this January's monthly calendar. So when we say that video game retail sales jumped 9 percent in January, that's not a fair comparison: January 2013 was a five-week month, whereas January 2012 was only four. With some simple math to adjust for the difference and estimate what a four-week January would have been, overall new retail sales across hardware, software and accessories is down an estimated 13 percent, from $765.6 million in January 2012 to roughly $667.8 million in January 2013.

The Wii U

While the NPD no longer provides specific sales numbers for hardware, a representative does tell us that sales of the Wii U hardware for its first three months on the market are down 38 percent from what the Wii's numbers were at that same point. We're told by someone with access to the NPD's data that sales for January were "well under" 100,000 units. By our estimates, sales were somewhere between 45,000 and 59,000 units for the month, which is lower than any of the three previous-generation home consoles sold in their worst months, with the possible exception of a recent performance by the original Wii. Similarly, we don't know any software sales numbers, but from NPD's report we can see where Wii U SKUs of multiplatform games compare to other SKUs, and it doesn't look good. In instances where a game exists on both the Wii and the Wii U (Just Dance 4, NBA 2K13, Madden NFL 13, Skylanders Giants and FIFA Soccer 13), the Wii version came out on top every time. In Madden's case, it was even outsold by the portable version for Sony's ailing Vita handheld.

Top 10 software chart (SKUs combined)

1. Call of Duty: Black Ops II (360, PS3, Wii U, PC) 2. Far Cry 3 (360, PS3, PC) 3. Just Dance 4 (Wii, 360, PS3, Wii U) 4. NBA 2K13 (360, PS3, Wii, Wii U, PSP, PC) 5. Madden NFL 13 (360, PS3, Wii, PSV, Wii U) 6. DMC: Devil May Cry (PS3, 360) 7. Halo 4 (360) 8. Assassin's Creed III (360, PS3, Wii U, PC) 9. Skylander Giants (Wii, 360, PS3, 3DS, Wii U) 10. FIFA Soccer 13 (PS3, 360, PSV, Wii, Wii U, 3DS, PSP)

By the numbers

Video game hardware: $205M (+4% actual, -17% adjusted) Video game software (console, handheld): $373.1M (+1% actual, -19% adjusted) Video game software (console, handheld, and PC): $392.9M (Flat actual, -20% adjusted) Video game accessories: $256.6M (+30% actual, +3% adjusted) Total video game sales: $834.7M (+9% actual, -13% adjusted) Estimated used game, rental and "other physical" sales: $141M Estimated digital sales: $382M Total estimated video game spend in US: $1.3B