Gamecube Bonuses:
If you've played a bunch of Mario Golf: Toadstool Tour for the Gamecube, you can use a link cable to download tournament ranks, stats, and any experience earned by a player used in both games. You are also elligible for bonus players in Advance Tour if you've met certain conditions in Toadstool Tour:

The Mushroom Tournament:
Beat every tournament to unlock the ability to compete against Mario in the Mushroom Tournament.

Thanks to Revolution readers Big Bad Dad, Dubious_D, and Ethan is Awesome!