You never know what is inside. If you do research before participating you know what you are waiting for. But you can do research and discuss it first. Yeah you can not forseen whether it will have a growth but you can save yourself from participating in scam. The best way to invest is to buy and wait until the price go up. Pay attention whether the projects has a ready-made product as it is some kind of guarentee that it is not a scam as well as long termed activity before ICO. Do not sell until you get profit. It is an indicator that team goes stright to thir goal and will not give up. But this move is also risky and depends on the bounty that you do.