Here you can set how many
credits a user gets for sending someone to their referral page.
With this function you can give your users credits based on each daily
unique hit they send to their referral page, reguardless if the user
signs up or not.
One thing to note, this gives credit per unique visitor to the SITE
that day, not to that particular referral link. For example
if User #2 sends someone to his referral link, then User #20 sends
that same person to his referral link, only user #2 will get credit
for that unique visitor.