This works for you too. Your players are yours for life. It helps you build up a player base as you grow. Once you have done that, you can become a full time affiliate.
I personally will not sign with a program that does not promise the player for life.
Also, in programs with several casinos you have the problem of cross promotions. You send a player to casino X and the program promotes casinos Y and Z to this player.
Shouldn’t you get paid for what your player brings to the other casinos? You are the one who sent the player!
Yes, we all send some players back to casino groups or even specific casinos after they were alread signed by another affiliate. It has to be regulated one way or another, and popular vote decided again and again we want life long players. Last time this vote was cast recently in the Referback vote.