I have tried it and I only achieved to double my money. In my opinion you have to be really careful and really really not greedy to make money with this. You can make money but not much.
I think what you should do if you want to invest, it's check top HYIP websites in HYIP explorer sites, and invest little money on them like $15-$20, on few of them. Than the next time re-study them, re-invest.
But for a good income, not possible in my opinion, if you invest for long-term like even 1 month, your money will be lost, specially if you invest a lot of money.
So I did it and i did it with these rules:
1. Analyse the HYIP websites every time I invest.
2. Never invest more than $20
3. Never invest for more than 1 week ROI