WE had all but given up on videogames at home and everyone's Atari 2600's were gathering dust when this was released. Super Mario Bros was just unbelievable and everyone would play it for hours. While I am quite certain that someone else would have come along if Nintendo didn't they basically saved the video game industry. I'm not sure about the specifics but I want to say that originally Nintendo wanted to team up with Atari rather than compete with them but Atari, in their infinite arrogance / ignorance declined the offer. Whoops!
RE: The magical MMC chip in NES cartridges