Participated at pre ICO is more benefit than you invest your money at ICO, when you make investment at pre ICO you got much coin with lower price than you are joining for investing at ICO time.
Yup thats a source to be a good earner as for participating you will not have to invent anything but you will get profit by using your information and knowledge but you will not have to use your money. if you want to take part a an investor then try with promising coin and hold for long term never trust any website which is not worth trust.