Actually, it depends on the card. While some cards, such as the NES games (Donkey Kong, Mario Bros., etc.) require you to scan the ten strips on five cards, others, such as the Eon Ticket for Pokémon Ruby and the Ice Climbers Animal Crossing Card are more like "keys" that just unlock existing events and data that are pre-programmed into the game.
Depending on how it's used, some of it, like the SMB3 level cards, are really cool.