There is this issue with Gran Turismo 5 Prologue numbers. Many people expected it to top 1 million units in the first week and are dissapointed now.
To clear up the situation: When talking about Pre-orders you have to keep in mind that there are user-preorders and shop-preorders.
User-preorders are the copies preordered by actual gamers who want to buy the game at the first day.
Retail-preorders are the copies preorderd by shops / retailers --> these copies do not always sell during the first days, it is just the number of units lying in stores.
In the case of Gran Turismo 5 Prologue those 1 million units are retail preorders, meaning there are 1 million copies available in stores. We have no information about user-preorders, though.
I hope this explains the issue a bit better.
