How can a sponsor pay 35.00 per free signup?

[LowryBigwood]

I can't seem to figure this out...

How can a sponsor pay 35.00 per free signup and others can only pay you 25.00 per $1 trial? That is a huge difference when you add up the extra you would make on more sales (maybe?) along with 10 more bucks per signup. I would think free signups would generate more chargebacks, am I wrong on that?

So, what am I missing? Why such a big difference in what one sponsor may be able to payout over another one? I was thinking a points / prizes program may be part of it, but what else might allow the payout difference?

Lets assume both programs are established programs.