Voucher System 

An interested customer is obtained through invitation by e-mail to visit a shop and purchase products. This e-mail is attached to a unique code which corresponds to a certain amount of credit points (voucher). When they make a purchase, they can redeem these credit points by inputing the unique code.

If a customer states in his registration that he has been recruited by another customer, then the referring customer gets credit points. The new customer gets a discount with his first order.

Somebody can enter a voucher code if he concludes an order. Then he will obtain a discount. In table fe_users there is a field given for this "tt_products_vouchercode" which contains the used credit entry code.