Use data explorer to get a list of users who signed up via invitations

I think the invite table was split at some point. Try this one and see if it works for the newer info:

SELECT iu.user_id, 
       i.invited_by_id AS invited_by_user_id, 
       iu.redeemed_at AS reltime$time 
FROM invited_users iu
JOIN invites i ON iu.invite_id = i.id
WHERE iu.redeemed_at IS NOT NULL
ORDER BY iu.redeemed_at DESC