Free Referral Sites and IFW's... What??? Thats not free!

Ok, I just wanted to get an education into these so-called IFW's and their hybrid "IFW-CPA" sites (and offline methods).

So...I joined up to "Anything4Free" site as it is touted as the largest IFW trading site.

What I don't get is why everyone is calling this "Free". To complete a "referral" most of these sites require you to pay money for the "offer" - so, why would anyone that you are trying to get to do this want to? Why would I want to (as I have to sign up for this stuff to be able to then refer others, or in the terms of IFW's "go Green").

A lot of this stuff (the referral offer) is pure crap too. Other stuff is good, but not anything I want or need. The IFW site is trying to perform customer acquisition (at least I think that is what they are trying to do) and selling the leads to the companies whose offers were completed. So why are these offers not "free" as the name implies that they are?

And if these Trade sites are so busy, then how are the marketers making money when they have to keep spending it on completing these referrals?

Thanks for any info on this, and yes I am just learning about it, but wanted to know how these kinds of sites work.

Thanks!

-DTM