| Week | Halo 3: ODST | Halo: CEA | Net Difference |
| 11 | -- | 18,654/185,178 | -- |
| 10 | -- | 15,966/201,144 | -- |
| 9 | -- | 21,041/222,185 | -- |
| 8 | -- | 37,234/259,419 | -- |
| 7 | -- | 53,530/312,949 | -- |
| 6 | -- | 29,228/342,117 | -- |
| 5 | 400,944/400,944* | 29,462/371,639 | -371,482*/-29,305 |
| 4 | 47,793/448,737 | 39,437/411,076 | -8,356/-37,661 |
| 3 | 83,191/531,928 | 64,066/475,142 | -19,125/-56,786 |
| 2 | 110,957/642,885 | 79,085/554,227 | -31,872/-88,658 |
| 1 | 111,014/753,899 | 109,711/663,938 | -1,303/89,961 |
I'm not sure if Halo CEA will even get to 4.5 million in lifetime sales now. At least ME3 isn't disappointing.
| Week | Mass Effect 2 (360) | Mass Effect 3 (360) | Net Difference |
| 19 | 1,532/24,593 | 17,069/296,252 | 15,537/271,659 |
| 18 | 1,272/25,865 | 17,073/313,325 | 15,801/287,460 |
| 17 | 1,396/27,261 | 15,827/329,152 | 14,431/301,891 |
| 16 | 1,578/28,839 | ||
| 15 | 1,979/30,818 | ||
| 14 | 5,183/36,001 | ||
| 13 | 7,223/43,224 | ||
| 12 | 9,944/53,168 | ||
| 11 | 16,351/65,519 | ||
| 10 | 19,966/89,485 | ||
| 9 | 35,852/125,337 | ||
| 8 | 21,379/146,716 | ||
| 7 | 23,306/170,022 | ||
| 6 | 12,794/182,816 | ||
| 5 | 25,808/208,624 | ||
| 4 | 37,877/246,501 | ||
| 3 | 64,655/311,156 | ||
| 2 | 79,129/390,285 | ||
| 1 | 85,497/475,782 | |








