Base on my experience many icos are scams and also they are not successful and most of the ico's failed to reach its soft cap. That's why you should be picky when choosing a ico especially if your investment is huge because it would be a big loss to you if the ico failed and i dont pick the ones with the coins that are not that good enough to reach or to advertise their coins. And also, knowing the team of the ico you want to invest is the best thing you can do in order not to be scam at all.