With 45 Million PS2s sold the PS2 only sold 984,598 pieces of software
With 16 Million Nintendo DS' sold the DS only sold 830,485 pieces of software
With 10 Million PSP systems sold the PSP only sold 323,307 pieces of software
The fact of the matter is that most gamers are not obesessive enough to buy more than a couple games a year; if they own a system long enough (say 5 years) they will end up with a library of 20 or so games. Systems which have reached a mainstream market rarely have a (particularly) strong attach rate ...