Imagine being able to get expensive gifts, or cash equivilant that you otherwise wouldn't be able to afford, all for free on the internet. Freebiejeebies works by a new type of internet marketing known as Affiliate Marketing, click on the link to see a detailed explaination from Wikipedia on how this works.
It is no different from what we've all seen when Sky TV offer vouchers to get your friends to subscribe to their HD service. However you don't get tied to expensive contracts, and instead you take out a free trial such as with LOVEFILM, or a website builder trial with Intuit, these companies then pay a referral commision which pays for your free wii, free iPhone 3G S or whatever other expensive free gift you want.
If your still not convinced that this works (I don't blame you if your not, I was skeptical at first!) take a look at the proof page