I hear that they take 10% of profits weekly. Too bad, I wish I could get a better answer than that because they don't tell you the terms for investing.
so assume that 10btc is wagered a week. the percentages show negative ev on all of the odds a player can choose.
(-10BTC)(0.495)+(9BTC)(0.505)= -0.405
(Investors Loss)(chance of losing)+(Investors Profit)(chance of winning) = (Expected Loss per 10BTC wagered)
At a glance, that looks correct for a single wager (which is a real investor worst-case).
However, assuming that bitdice.me works like JD, investors are given commission free earnings on any investing loss since the last commission was taken (a high water mark). Which has an interesting effect with a small amount of wagers: every week you have >= 0 profit, investors are -EV. However, when investors are at a loss: they are now +EV (since there's no 10% haircut), which means over an infinite amount of weeks you are still +EV
There's certainly different ways to do it. For instance in MoneyPot we take a commission in such a way that every individual bet is still +EV for the investors:
https://www.moneypot.com/faq#what-commissions-do-you-charge-