As discussed elsewhere on meta.crypto, we need more questions from existing private beta users.
Can they be contacted? If so, what pitch should we make?
One element of it that comes up for me is to remind them that Area51 users are limited to only 3 active commitments, which are only satisfied when they make sufficient contributions (I'm not sure how much), or after the sites they've committed to make it out of public beta. Since new Area51 topics come up regularly, if you want to be involved in new ones, you have to pitch in on the ones in progress. (Links to the exact rules would help.)