Just a random thought, but have you considered graphing the order in which invite codes are used (or attempted)? I'm curious what the optimal strategy would be to try to get one (start from the top, start from the bottom, start from the middle?).
Yeah, that crossed my mind actually. That would be pretty interesting. Anecdotally I can say of the first batch, they went 3, 10, 9... (don't know the rest, they went fast).
Interesting thought. People are definitely not going top down... for example, two of the first invites used were the 3rd, and the last.