The dealer does it on and off. Sometimes they have a huge radio promotion. They will have BarBQue and DJ's on Air. Huge crowds and a real fun environment. They usually give away T-Shirts and Hats, Can Coolers, the usual shwag. Sometimes its just a few of us bashin around on a Sat morning. Its always a good time, and you always meet some fun people.
Edit: Oh, and you always trash a good set of knobbies

My motard tires were too slippery on the marble-like dirt.