Yesssss!!!
I've been wondering about this, I have a bunch of friends that want to join but (as greedy as it sounds) don't really want them to join until the referral program is up and running xD .
Theres a few ways they can implement it:-
1.just a flat out SP amount per user
2.A small % of what they receive from blogging or curating
3.and ontop of it all this could work on a scaling system eg. first 10 invited is 2% next 10 is 4% ect ect.