That's what I have also observed about these paid to click sites. I have already conditioned myself to distant myself from any payment of sort.Apart from HYIP and cloud mining sites that are known to go scam, there is also PTC sites that ask you to upgrade your account so that you can earn more. Most of the time, you will pay money to upgrade your account but it ends up being a scam. You will not be earning more as they promised or they stop paying everyone.