Gran Turismo 4 JP Launch
The Japanese launch of Gran Turismo 4 has been a roaring success, with Gamespot reporting that the game sold one million copies in two days. From the article: "The game's shipment beats the Gran Turismo series' record of 1 million copies in three days, set by Gran Turismo 3 from April 28 to 30, 2001. Overall, the franchise has sold 36 million cumulative copies worldwide since the title was released in 1997." They also have a piece discussing their impressions while testing the japanese version of the game.
GT4 did not sell a million copies in two days, that's merely the number of copies shipped to retailers. The actual sales figures are around 635.000 copies in the first week, which is still very impressive, and about 15.000 copies more than GT3 sold in its first week.