Only one person wins at this and that is the admin who makes them and decides when to pull the plug. Only way sites like this could be good is if admins do not get greedy and have everything 100% transparent and have something real to make returns in providing such returns. Am thinking to do one that is fully transparent on transactions, wallets, registered and legal and provide a progressive interest rate that is not guaranteeing any fixed RIO and also has funds that are held in escrow as a backup fund that is held for payments and topped up when gets below x amount. So sick and tired of the scams going on, people losing funds and getting ripped off. One day you might see me making a topic in here making a change for the future for everyone, but right now its just thoughts and ideas maybe come to light one day and you find something that will outlast and lead the way.
The only real "investment" game I'd seen that lasted for a long time without a scam was fishbitfish.com, which was based on whichever address was given more Bitcoins, paying out to the people who bet on the winning one.