Smash Bros is quite a clever marketing tool (even though I dont believe Nintendo have engineered it that way). People can pick it up recognising Mario, Link or Pokemon and then become familar with other lesser known Nintendo franchises like Kirby, Metroid and Pikmin. Playing Smash Bros influenced me to pick up Metroid Prime and I doubt I'd be as excited about Kid Icarus if it hadnt been for Brawl.