What referral system do you use for your project/business?

We are still thinking about this idea, but I will share it with you anyway. We are offering https://www.myfocusspace.com for free now and we were thinking about the referral system we would like to put in place. One of the ideas was to offer everyone who brings 1 person on the platform a coaching session with a coach or a therapist to help them identify and clarify their own plans/tasks/goals. Any thoughts? What referral system do you use?