Maybe when discontinued or a new model comes out. If they keep it on the market along with fresh games there's no reason for it to stop selling anytime soon.
Nope, sales curve is pretty consistent, you can see it increase, plateau, descrease and dwindle. If platform holders really could keep the same system selling they wouldn't take the risk to put a new system on the market with 0 install base and games. They usually launch the new system when the current gen console SW sales start to decrease. You can look at PS4, HW sales have started dropping for about 2 years, but SW was still good, but you can see it is nearing the drop as well. Why do you think if Sony kept it around for let's say another 10 years it would sell another 100M?
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"