Decided to look back at Xbox and Gamecube sales at the start of their life in US (VGChartz doesn't offer this info sadly). Have not done PS2 vs PS4 because I do not have the first 8 months NPD of PS2, if anybody has those and would like me to add them in I'd very much appreciate it! From what I know, the last 6 months of it's full first year, PS2 did 300k+ every month. But a lower launch means PS4 is ahead in overall sales.
WiiU Vs. Gamecube.
As you can see WiiU has never outsold Gamecube in any month and so the gap has grown to 1.77m. The following months for Gamecube show, 124k, 127k and 100k, after that it's still above 100k and even achieves 750k+ and 1.163m in Nov and Dec respectively. Suggesting WiiU is never going to overtake Gamecube in the US.
| Date (Last Gen) | Month | Gamecube | WiiU | Difference | Cumulative Gap (Gamecube Favour) |
| Nov-01 | 1 | 663,000 | 425,000 | 238,000 (GC Favour) | 238,000 |
| Dec-01 | 2 | 573,000 | 460,000 | 113,000 (GC Favour) | 351,000 |
| Jan-02 | 3 | 62,000 | 57,000 | 5,000 (GC Favour) | 356,000 |
| Feb-02 | 4 | 78,000 | 66,000 | 12,000 (GC Favour) | 368,000 |
| Mar-02 | 5 | 111,000 | 67,000 | 44,000 (GC Favour) | 412,000 |
| Apr-02 | 6 | 82,000 | 37,000 | 45,000 (GC Favour) | 457,000 |
| May-02 | 7 | 111,000 | 35,000 | 76,000 (GC Favour) | 533,000 |
| Jun-02 | 8 | 213,000 | 42,000 | 171,000 (GC Favour) | 704,000 |
| Jul-02 | 9 | 138,000 | 30,000 | 108,000 (GC Favour) | 812,000 |
| Aug-02 | 10 | 128,000 | 32,000 | 96,000 (GC Favour) | 908,000 |
| Sep-02 | 11 | 167,000 | 91,000 | 76,000 (GC Favour) | 984,000 |
| Oct-02 | 12 | 168,000 | 50,000 | 118,000 (GC Favour) | 1,102,000 |
| Nov-02 | 13 | 468,000 | 220,000 | 248,000 (GC Favour) | 1,350,000 |
| Dec-02 | 14 | 619,000 | 481,000 | 138,000 (GC Favour) | 1,488,000 |
| Jan-03 | 15 | 81,000 | 49,000 | 32,000 (GC Favour) | 1,520,000 |
| Feb-03 | 16 | 165,000 | 82,000 | 83,000 (GC Favour) | 1,603,000 |
| Mar-03 | 17 | 165,000 | 70,000 | 95,000 (GC Favour) | 1,698,000 |
| Apr-03 | 18 | 101,000 | 48,000 | 53,000 (GC Favour) | 1,751,000 |
| May-03 | 19 | 84,000 | 61,000 | 23,000 (GC Favour) | 1,774,000 |
Here is the Xbox Vs. Xbox One charts. XB1 has done better than Xbox Original ever since launch save for this month. April 02 saw a price cut announcement (similar to this month) thus May 02 sales are much higher.
| Date (Last Gen) |
Month |
Xbox |
Xbox One |
Difference |
Cumulative Gap (Xbox One Favour) |
| Nov-01 | 1 | 722,000 |
909,000 |
187,000 (X1 Favour) |
187,000 |
| Dec-01 | 2 | 700,000 |
908,000 |
208,000 (X1 Favour) | 395,000 |
| Jan-02 | 3 | 128,000 |
141,000 |
13,000 (X1 Favour) | 408,000 |
| Feb-02 | 4 | 139,000 |
258,000 |
119,000 (X1 Favour) | 527,000 |
| Mar-02 | 5 | 136,000 |
311,000 |
175,000 (X1 Favour) | 702,000 |
| Apr-02 | 6 | 78,000 |
115,000 |
37,000 (X1 Favour) | 739,000 |
| May-02 | 7 | 229,000 |
77,000 |
152,000 (XB Favour) | 587,000 |









