Warning! do not right click and do “copy link” because the link actually points at http://www.kongregate.com/accounts/USER/referrals instead of http://www.kongregate.com/accounts/?referrer=USER like it logically would. I didn’t realize this at first and had someone sign up using the copied link and they were obviously not a referral of mine afterwards.
P.S. Yes, I have submitted this as a bug already =)