I feel it so because I have been thinking of posting similar concept as a proposal. Now, your idea is just perfect. Thanks I don't have to write it myself.
But then I must say that if this is taken into account by the Steemit leadership and studied very well for its feasibility and sustainability, then we may be able to dominate the world as the major social media platform. Referral is one of the fast means of making the world know Steemit. Those 50 billion people that will get in is I think more than enough incentive for us all. And that will not be the terminal figure anyway.
RE: If the total affiliate rewards in a system are a "fixed constant" percentage of the token supply then referral programs can work