Originally Posted by Maza
How long is the lifespan of a G/S cartridge, generally? And how much does playing with it affect it?
5 to 8 years. Maybe more maybe less. I don't think playing or not playing will have much of an effect. Most Gameboy games have some kind of battery in it but you don't see them dying. I believe it's the crystal oscillator, which keeps the time, which has the biggest effect since it is constantly using the battery's energy.
You can however replace the battery with a newer one which should have a lot longer life.