In alt.games.video.sony-playstation3 The alMIGHTY N wrote:
I think the question was basically, "If you the disc works in both the
Playstation 3 and the Playstation 4, what incentive would most people
have to pay for the new Playstation 4?"

This.

If you have a PS3 already, and new games work on it, why buy a PS4?

If you don't have a PS3 at all, why would you want to spend more money on
the PS4 when the PS3 plays the same games?

Does anyone really think we're going to see a huge jump in graphics
between the PS3 and PS4, much less enough of a jump that will make people
want a PS4 when the PS3 plays the same games?

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It's not broken. It's...advanced.