My question is clear and simple- Why do most dice sites have a max payout of 9900x while, satoshidice , being a dice site as well, has 64000x max payout?
Take a site like primedice, there's 10,000 discrete options [0.00, 99.99] so the most risky bet is having a 1 in 10,000 chance of winning. With a house edge of 1%, that means the most you can win is 9900x
The more discrete options (i.e. values after the decimal) the more possible risky bet possible thus higher payout. I think JD for instance uses 4 digits after the decimal, which means the riskiest bet would be a 1-in-a-million, which would allow them to have a max payout of 990000x
On a side note, before you play on satoshidice, you might want to checkout the latest in their thread