Why to run your affiliate links through a redirect:
1. You can place tracking code on it and know how often it’s clicked on. You can see if this number matches what your affiliate network is showing.
2. If you have many links to your offer on your landing page, and the offer gets pulled, or you want to test other offers with the same landing page you only have to change the link once (on your redirect).
3. It can help to hide the affiliate link from your visitors.