A PTC "aka paid to click", is a site where advertisers pay the website owner to distribute their ads to its users. The users view these advertisements and in return, receive money. There are many different kind of PTC sites and you can expect to earn anywhere from 0.001 to $0.02 per each advertisement viewed "sites that offer a higher rate, ranging from $0.01 - $0.02 are known as ( Bux ) sites". There are many scamming sites out there on the web and only a few "legit" ones are actually paying and not planning to steal your money in the short future. All PTC sites have a timer for each ad before you are credited, most sites have a timer ranging from 15-30 seconds for each ad. Once the timer has completed, you will receive credit instantly to your account.
Referrals are people who have used your referral link "suplied by each website" during registration. Most sites give users the option to remove your name from the referrer box if they like to, while others make it impossible to remove your name or do not show the referrer box at all to make things fair, since they did use your referral link. For every advertisement your referral views under your account, you receive money. Most sites offer you anywhere from 50% - 100% for your referral earnings. Many sites offer "renting referrals" which means you purchase referral "rent" for a lengh of time from the site directly, usually 30 days at a time or you can extend the referrals for any amount of time you would like to. These rented referrals are people who have joined the site without a referrer.
Most PTC sites offer payments by Paypal and Alertpay. These are online payment processors which are legit businesses. You can use these funds for online purchases or you can connect your bank account to these online processors and send your money to your bank account via bank transfer.
X Avoid sites that do not have a forums
X Do a google search on the site for scam warnings
X Read the "terms of service" & "FAQ" for each site
X Avoid sites that do not offer fast or instant payments