Your best bet is to find the casinos that are here in bitcointalk and see for yourself, how long those casinos have stayed in business and diversify your risk by investing in several casinos instead of a single one. I'm waiting for bustabit to accept investment.
You got many good options to choose for investment and no need to wait for some particular site to accept for investments. As long as you diversify your funds, then you're safer in these investments.
You can make money with any amount, but you shouldn't ever invest or gamble with money that you can't afford to lose.
In investment, less chances of losing all your investments and you will still get an opportunity to withdraw your funds but in gambling either you will lose all or win.
20% chances will incure if you invest in gambling and yet you enjoy playing on it. Investing do positive results you gain revenues in the future of your btc and enjoy greener pasture of it. We must think about the best option at all times investment in any matter is not easy at all it requires tough decisions.