Affiliates+mms plugin: sign up for the affiliate program only - no access to protected content?

I have both the membership and affiliates plugin installed (still trying to get the affiliates plugin to work properly (that problem is addressed in another post), but I thought I'd still ask my fllowing question:slight_smile:

I have set up a limited time free trial membership, as well as a paid membership level.
Now I was wondering how I can get people to still sign up for the affiliate program, without having to sign up for any membership level, so without getting access to the protected content...

This includes members that have signed up for the free trial, and let their limited time membership expire, without signing up for the paid access. How can I make sure they can keep promoting their affiliate link?