Would love to join as I love tournaments but unfortunately it's just not feasible time-wise. It's hard enough for me to schedule a single series a week for the Gokodom style tournaments. Dominion for me is more when can I find time rather than who do I want to play. And then even when I find time it's usually just enough for a few games.
Good luck getting this going. You've got a tough road going forward trying to start this up. As others have said people here on this forum are quite content with general forum discussion and periodic Gokodom tourneys. You're going to really need to do something special and unique to make your site grow and attract high caliber Dominion players.
Players already have the Isotropish leaderboard to mark their growth and progress. It's accurate and updates instantly and provides comparison against EVERY player. You've got to do something with tournaments that is unique from player comparison because let's face it, no one is going to become super active with a tournament site to see who's better because they already have a good leaderboard.
You've also got the problem of reputation. At this point, no offense to you, you have almost no reputation within the Dominion community other than being the most tournament enthusiastic person in the forum
So with little reputation you are trying to get players from an established forum to play in tournaments run by someone with little reputation. People like Kirian and Qvist can run tournaments from here because people on the forum know them and respect them. People on this forum are more likely to play in a tournament run by someone who's been around for awhile.
So what do all of us have in common here? We're all Dominion nerds who love to play Dominion. Make your tournament website something that will appeal to a Dominion nerd. Perhaps you could do something with material gain (doesn't need to be monetary). I know a ton of people here would be like a herd of monkeys over the last banana if a tournament had some sort of sweet Dominion related art for a prize like a blown up print of card art for instance. There's also the custom coin token treasure chest that I've seen floating around. Give people some sort of motivation for why
your tournament site is unique from playing a tournament hosted on the DS forum.
That's all I've got to say now. I'm not trying to dissuade you from this because I think it's an awesome idea. You've just got a lot of things to overcome to make your site popular and active.