If you're interested you can sign up to be notified when pre-launch tix are available; that's the action available today.
Since conference is quite soon anyway I thought it would be a better move to just open the registration and then do the promotion, but hey I'm sure you guys got something in your mind like defining the price based on interest, or something like that.
Oh, and we're not defining the price based on interest; the price is pretty much set (see my comment on this thread about price).