When looking for an affiliate program with https://bittrex.com/ then it is very difficult to find their refer a friend affiliates codes.
The only way of trying to get onto their refer a friend program is to contact directly to see whether they will allow you to promote them.
I have several accounts set up with bittrex and would promote them more for bitcoin wallets and exchange if the referral codes was easier to manage.
If you want to set up an affiliate program with them then leave a review below and comments to why you feel you should be considered?
We will regularly share this page on their email and facebook page to see whether any of you can be accepted.