It did over 3 million first week to be the biggest Ubisoft launch ever... AC3 did 3 million first week.
Edit - My bad... AC3 did around 3.5m first week... a little over 3 million
http://www.shacknews.com/article/76537/assassins-creed-3-sells-35-million-ubisoft-estimates
Watch Dogs beat it.
2 million will be only US
those are first day sales. first week are different.