Hey Justin,
I've been working on my own membership site for the last few months and will launch it in the coming weeks. I think this is a good idea for a thread and I hope you don't mind if I chime in here with my own experiences.
First, I think your decision to delay the monetization of the site until next season is a good one so you can use the remainder of this season to build a user base and tweak the kinks out of your system.
You will need to perform some exhaustive accuracy test if you want to attract users. If I'm a prospective user, your good performance in a few contests won't be enough to convince me to shell out my hard-earned cash. Obviously not something you need to do right away, but something you need to think about.
It's a good idea to break your project down into parts, but choosing a domain name shouldn't be Part I. First, you need to do research on your target market to determine what they're looking for that isn't currently provided. What services would be helpful? What would your market be willing to pay for those services? How big is your target market? Designing a survey at a site like
www.surveymonkey.com and getting answers from your target market is the first step to determine how you should proceed further. Hope that was of some help.