Wanting to customize the affiliates page to include none paypal dependent signup

I'm trying to setup a referral tracking system for none monetary benefits. I'm working with a nonprofit that wants to build their email list by giving rewards out for how many of their friends signup.
The word "affiliate" will through visitors off and diminish the effectiveness of our campaign. Is there documentation that will enable me to customize this plugin to say referral and kill the Paypal email requirement?