I can tell you that the biggest referrer so far has referred 100+ people who have earned her 7,225 points so far. She emailed her list about it 4 days ago.
In her email she emphasized both the points system that can earn you free software AND the how the community can provide lots of help with your questions/answers -- and how quickly people come in and answer the questions you ask.
It's obviously worked very well for her.
I've set my signature. Have you? If not, CLICK HERE. (requires 250+ points)