Click the link and send someone a gift.
It will give you $4 off the gift card you purchase...so a $5 gift card would cost only $1.
I sent one to my husband. Took 2 min. He had to confirm and accept it but it went through fine. Some have to be sent in the mail but they tell you if they do
Seems it's YMMV - I did it on chrome and was logged in to my account
Some are reporting it works on one account but not another.