do you offer cash back to your ptc referrals?

Many people do this already. Some sites offer an amount to users for each referral that they recruit and many people have seen that it is advantageous to offer to share that amount with their referrals. It obviously depends on whether your referrals can trust you to actually pay them. If you don't, you will very quickly lose credit where ever you go. Perhaps a more solid business model would be to pay each referral individually a proportion of the amount they actually earn for you by their activity on the site. This would require some organisation and also a system of verification so that you knew how much each of your referrals was actually contributing - not data that is always easy to find since referral income is usually quoted as a total figure.

and how can you pay them this small amount of money ??? I don't think it's possible ... can you pay this small amount through paypal or what ???

no its really not good to pay any money to your referrals as you may never know that the site to which you are referring them is legitimate or not as sometimes you may have to spend money from your own pockets and you will not be getting anything in return so better don't fall in such trouble. Try to get more referrals from your websites or blogs also try some of traffic exchange sites such as trafficswarm.

i don`t think it is a good idea because they don`t do enything for the money that you recive. that money come from the site not from them