ROM Cartridges. Lifespan, and other tidbits

Well, after discussing all things that can go wrong with a floppy disk to corrupt or destroy it, it makes me wonder about another vintage media format: the cart. How long will they last? Why does blowing on them help? (mosture? cleaning action?) Are some better than others in terms of longevity? Can they be refurbished ? Remember when folks would publish apps on carts to enhance the copy protection ? Remember the ones like Starfox for the SNES that had coprocessors embedded on them? Those were neat. Seen the crazy prices for rare Neo Geo carts? $400 bucks for "Twinkle Star Sprites" ? Sure! I have some 90's consoles in my collection and I fondly remember a few systems that took carts that family and friends owned back in the 80's and 90's. I thought the Colecovision Adam was awesome. My cousin had one and I was so jealous. The C64, 80's 8bit Atari PCs, the IBM PC Jr, and others all had cartridge ports, too. -Swift