Well if that is 1 million active users I would bet that there are still many more 'used' keys, myself being a Mullvad user have used about four different accoun

Well if that is 1 million active users I would bet that there are still many more 'used' keys, myself being a Mullvad user have used about four different accounts, since you can just generate a new one. I don't know if this really makes a difference though