Modern Warfare 2 sells an estimated 7.2 million copies on the first day of release

"Early data is in and the confirmation that Modern Warfare 2 will become the fastest-selling game of all time isn't a big suprise in itself, but the margin with which it looks to take the record is astounding.
VGChartz preliminary day one figures puts the sales to date (including the midnight launches) at over 7 million copies worldwide across Xbox 360, PS3 and PC. Around 55% of sales are on Xbox 360, 33% on PS3 and the remaining 12% on PC. In terms of regional breakdowns, over 4.2 million units were sold in the Americas (3.7 million USA), 1.2 million in the UK and 350,000 each in France and Germany.
Based on the day one figures and the Tuesday release, week one figures should come in at close to ten million units which smashes the 5.92 million week one record set by Grand Theft Auto 4 last year and positions Modern Warfare 2 as the most successful game launch of all time.
In fact, even on a single format (Xbox 360), week one sales are projected to come in at around 5.5 million units - this alone is enough to be the fastest-seller of all time, even without the PS3 and PC versions"
Source: VGChartz, 11th November 2009