The first issue that I have found is the minimum withdraw requirement the most PTC sites apply. Any minimum of $5.00 or more takes several months or longer to reach without any referals especially if the average clicks per day is around 4. With 4 clicks a day an individual is earning about $0.04 a day at the website which with no referals will take over 4 months to have a minimum amount of $5.00 in their account. Several PTC have came and gone long before 4 months so it is important to find more established PTC sites when an individual is not able to get referals.
The next issue with PTC sites is that some do not pay free or standard members. An individual needs to make sure that the PTC pays both free/standard and premium members before clicking. The PTC sites that do not pay free/standard members usually allow these types of members to use the earnings for advertising with the site. Make sure to read the TOS and FAQ pages of the PTC site to make sure that you are able to use your earnings if you cannot cashout as a free/standard member.