Sony's numbers have always been iffy, so beware..

the PS2 numbers confuse one tracking method with another, both of which are quite manipulated, production shipments up to a point,and then sales to retail. A large pool may have been counted more than once on transition, and even then there's no estimate of what was actually sold to consumers, a lot of it may have been replacements believe it or not.

We're not gonna know how much the PS has really sold, particularly the PS2 because of these confusions. What Sony has paints a bigger number and we won't know the difference until a serious research method is applied. There's been serious talk that the PS2 was sold to less than 100 million consumer households actually.

Congratulations for being the best house of games too!

Errr Sony's own website has had the PS1 at 102.49 million for years... where have these additional consoles come from.

http://www.scei.co.jp/corporate/data/bizdataps_e.html

And as someone else said, 2 billion SW figure is too low.

Sony are really terrible at getting their figures right.

By this table...

PS1 = 102.49M
PSOne = 28.15M

TOTAL PS =  130.64M

And software maybe count just from Sony Producer.