This is quite a tricky problem. On the one hand, you want to spread distribution over as long a timeframe as possible to allow more people to participate.

On the other hand, the longer it is drawn out, the longer tonych is sitting on 90, 80, 70, 60, 50% of the total coin supply. It's hard to be taken seriously as a currency when one guy owns 90% of the total money supply (even if he promises to give them away for free at some vaguely specified later date). So, from this perspective I think you want to distribute coins as quickly as possible to eliminate the uncertainty associated with one person holding almost all the coins (whether he intentionally after maliciously and dumped the coins or I believe his identity is public so someone could steal or rob him off the coins).