Vanilla is a product of Lussumo:
Documentation and Support.
It would seem that the people who've been invited by other users don't get invitations; only the ones who've gotten theirs by requesting one from Google do.
Alright, I just got a new batch of 30 invites to hand out, much quicker than I expected. I'm allocating at least 10 of these for people here, maybe more, depending.
So before I start just firing these off, I need to know who has requested one here previously that hasn't been sent one yet. If you've been told one is on the way, and it hasn't been a week yet, let that week run it's course first, as apparently that seems to be the outer end of how long an invite might take to go through at times. I know we had a few slip through the cracks when D- and I were tackling the initial round, and I want to make sure that they get first crack at it if they've not been hooked up yet.