I read that there is an estimated 10,000 bitcoins gambled yearly (around 27.4 btc daily) on Mintdice. With 1% house edge then there will be around 100 btc in a year or 8.33 btc monthly earnings. I am curious on the size of the current bankroll.
I think this number is just an example, the current traffic on mintdice wont give that much number of gambled btc daily. Coming up to its current bankroll, as I remember their bankroll is more than 350btc when I checked it few weeks ago. It can be bigger now in case there are some new investors.
I haven't tried investing into any casino bankrolls but I do have some ideas since some relatives and friends did it some years ago. Betking bankroll investment then did very well like around 4% rate of returns monthly.
Bear in mind that there is no guarantees return on this kind of investment, there is always a risk of losing money once there are some whales who big win on the site. So invest what you can afford to lose only, don't spend too much just because you think there will be a x% of monthly return.