All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If those who get the discount do not pay money in exchange for getting it, then there is nothing wrong with it. As for creating more than one account to deceive those sites and make them believe that you have brought them new buyers, then it is not permissible because this is deceit and cheating, unless you know from these sites that they allow creating more than one account to bring them new buyers, then it is permissible.
Allah knows best.