Not sure if this is all that relevant or even accurate, but this article says over 30% of the units shipped may not be sold yet and yet the videogame charts site lists the PS3 as having 0.94 million units sold in Americas and 1.58 worldwide. I know that they also had the Wii selling 4 million units worldwide quite awhile ago, and then amended it to 3.5, while it's now standing at 3.67. I think the whole thing is pretty confusing because I can't tell if it's units shipped or sold and if the same method of documenting "sales" applies to every brand or not.