Hmmm... looks weird. Is there an official (or unofficial) explanation for this? After all, >4 billion bets should definitely smooth out all the statistical anomalies and give the expected figure. I think there are problems with statistics, often casinos hold promotions with bonuses and a reduced house edge (at least I read about such a promotion in a thread dedicated to investing in a casino bankroll) and apparently this gives such a distortion.
This particular site has an option to invest, so I don't imagine they would reduce HE as a promotion toll, as they'd need to pre-agree such move with all the investors first, which is not feasible.
But maybe the "profit" figure is indeed stated after deducting some other expenses (i.e. referral commission) and that's why it's lower than it should be. But that would probably be accounted for on DiceSites.
I'd ask in their ANN thread, but it's no longer monitored by admins.
Other similar sire,
Bustadice also is a bit off in the EV/Profit ratio, which stands at 82% after over 3 billions bets.
I think it's kind of expected for a low-edge games to have big swings i profitability. Max winnings settings also plays big part here, if you set it too high, if someone happens to win big, it could take a very long time to bring the profit close to the EV.
No fluctuations (large gains or losses of players) can matter over such a long distance.
In it, one of the forum participants describes his experience, and although he was an investor in one of the casinos, no one asked him (like the entire pool of investors) about holding bonus promotions. And there somewhere inside the thread describes the period when he suffered from these bonus promotions (players won a lot).