Paintball is becoming a very popular sport all over the world and there are very few guides on how to improve your Paintball game.
A membership site is just what this market needs. You can get a lot of really good free information on Paintball on the Internet, but you really have to dig.
People will pay $9.95 or $19.95 a month for this information in an organized fashion.
You could easily create things like strategies, reviews even interview expert Paintballers on all things Paintball and add it to your membership site.
Marketing this site would be easy. There are thousands of Paintball sites out there who would love to link to your site for a slice of your pie. IE, setup an affiliate program.
There are also thousands of paintball forums online that you could go to and talk about your membership site.