When the leaderboard was still up I noticed that 20 people seemed to control 70-80% of the supposed 500 ghs. My obvious conclusion was that the 500 was total bunk, more likely it was at least 2-3 times that floating in the market. So, at some point the operator simply had to write off most of that overissued khs or lower the reward drastically. Actually he has done both by now.