When someone start a HYIP, he spend money for the web site (hosting, script, design, advertizing etc.). The period in which current HYIP pay back depends on expenses. Admin of the HYIP expects to receive more money, than has spent, he will pay to investors. Here is the moment to earn in HYIP. Some projects work less than a week but others for 1-2 years before they they SCAM. It is real to earn in HYIPs, but it is important to be careful choosing projects, note signals, use various strategy. Usage of referral will increase process profit.