How it works once you've got an account here.
You sign up under whatever program you like. Once you send your sign up information and agree to stay active, if you did in fact sign up under your referrer, they confirm the deal and give you whatever number of points they advertised. You can then take those points and spend them on advertising your own referral link to whatever site you want. Basically, the higher the value, the more tempting the offer. It might also help to bring in original offers, as some of the more common programs have several people jockeying for refs. It's totally free and there's a referral system, as well, so what are you waiting for?! Remember to confirm BEFORE you validate anything. Also, there is a 5 day limit for you to not accept a referral for whatever reason.
(P.S.: Thanks for the help, Hula!)