BTW, for the record, I am a proponents of ICO regulation because I believe that 90%+ of current ICOs are scams.
If only 90% ICO is scam so 10% not a scam. If one of 20 ICO you choose to invest will make 20x in some month, you will make good money. So people invest in many different to find than one. It's a normal strategy.
Note that I said 90%+ (probably closer to 95%) but yes the strategy is to find that good 5% and make good money.
...and yes, you can buy several and hope one of them take-off. It is called hedging and diversification.