I'm a newbie but we all have to start somewhere, don't we?
I don't have first hand referral experience in getting referrals to Adult sites, but I do know how to do it, and have had people persuade me to sign up to sites.
Given that it's free to sign up, I would set myself a goal to get 10 per day. Some days I could get more. Some days I could get less, but the average would be about 10.