This was a "bonus" dividend then.
So how often and how much (estimate) regular dividends will be like?
Dividends are paid every month.
And, you can estimate the amount of the dividends yourself. Here's how:
Dooglus has been tracking the wins/loss of every bet made on SatoshiDICE each day
in this thread. (Check the last posts) He does this by tracking the bets through the blockchain.
Next add up the profits for the month. These profits MINUS expenses (server upkeep, salary, etc.) will be the entire stock dividend.
Then divided by 100,000,000 shares of stock. (Note: only 10,000,000 share are available to the public, the rest are held privately.)
Now you have the dividend per share.
Remember, GSDPT keeps an additional 5% of the dividend.
As an example:August 2012 profits MINUS expenses were:
BTC7,861.57
Profit divided by 100,000,000 = 0.0000786157 dividend per share
GSDPT keeps 5%, so after that the dividend per share would be:
0.000074684915