Well I know that the Nintendo Wii is in first and the Xbox is second so why is the PS3 last well I'm more of a Nintendo person so I didn't read any articles about why is it last place.
Many reasons, firstly because the Xbox came out for the PS3 and if you look the sales chart understanding that you can see the PS3 is catching up. As for why the Wii is in first, its mostly because non-gamers buy them, i.e. old people, little kids, technologically illiterate people.