I am looking for feedback from people that may have or do own tracks. If someone wanted to start a track what are the most important things to consider?

Things most people are not aware of.
Things that are important and things that are not.
Best size of track
Outdoor or Indoor
Classes
Scoring
Insurance
Time

MOST IMPORTANT! MONEY!!!!! and a good lap counting system.

Care to elaborate. I am looking for detailed information.

Another question I have is about sponsorship. I see tracks with banners hanging everywhere. Are they paying the track to hang those? Are local hobby shops usually receptive to sponsorship? What is typically "donation"?