The moment I don't have to do any work aside just investing my money and expecting a fixed amount paid to me over a period of time especially when the amount looks too good to be ignored then, my suspicions are always very high because I've been taught that nothing good which is supposed to last will just come with no strings attached.
That’s what most people want isn’t it? To not do any work, rather seat down there and keep earning money because they had a little deposit they did put in somewhere and to think of it, the profit is usually high.
Since they know you want it, they sell it to you and most people would buy in that idea so, the Ponzi scheme grows.
Having to identify these signs and back off is usually the best thing anyone can do for themselves otherwise, its always a matter of time before you loose your money.