casino has well reputation.
Not all companies do have a 2% interest fortheir investors,
Every company have their own explanation regarding the interest that their investors will receive.
One more thing if some of the companies as what you had just said had 2% interest, Then I think It is still profitable for a big amount of money that are going to be invested on those companies.
Invest on casinos that already have a good number of gambler followers. This will assure you that you will not have a problem on your investment and that it will continue to turn in profit. You have to study the gambling sites first before you give them your money. Make sure they have been around for quite some time and that they have a stable income.
This is only if you have a lot of bitcoins to invest. Sometimes, if you don't have enough bitcoins, you won't gain much in investing in the big casinos, as they have a huge bankroll with many investors. Sometimes, if you want a higher return, you'll have to invest in a smaller site that doesn't have as big of a bankroll, so that you can earn more.
Some small sites are trustworthy and won't run with your money, so you'll want to try to find one of these to invest in, so you can get a higher return with less investment. Investing is sort of like gambling in a way, OP, you'll need to take risks to get big returns.