[J S]

I would strongly suggest against making it a pure freeroll as you will be bombarded with freeroll whores, my god the freeroll whores. Instead, make it a smaller buy in with $$ added event and or prize added event.

You probably will not be able to limit it to ONLY players tracked to you... Reasons I say that is that you want a large number of people in the event I'm assuming and you want all of your 'regulars' (if you are doing this for a forum/community etc) to be able to play even if they do not have an account through you.

You also do not want to make a minimum post requirement in your forum unless you want tons of garbage posts and a lot of time investment managing it.

I would recommend a buy in, prize added event that requires them to at least opt-in to your newsletter, register with your forum, etc.

Even better is create a challenge of a series of tournaments where the points winner(s) at the end of the season win something special/big prize(s).