Probability of random key will work?
"People invited from the timer don't get keys, their accounds just get put straight into the beta. No keys there are all. People in the beta can receive friend keys given out at random, which they can then pass on to other people. These are only valid until they're used, at which point they're no longer valid. In addition to friend keys, Chris can just generate some new keys to give away when he has a reason to do so. Again, once used they're no longer valid. I don't know for sure, but I would be very, very surprised if there are that many currently valid keys. |