How it works:

Today all the companies are battling each other out on their advertisment and the small companies gets booted out of the scene and so these companies are now desparate to make income or just reach their minimum sales quota to pay the website like FreebieJeebies it is being payed by advertisers and sponsors to bring them new potential customers and take note that these companies are famous in someway and you might have seen them around. They get these customers for the sponsors by offering them gifts, in this case, a free ipod, iphone etc.,. Since the amount of money they recieve from sponsors exceeds the cost of shipping the gadgets, and everyone makes a profit. The sponsors get new customers, The site makes money, and you get a free gadget. So simple!

 
So what's the catch?
NONE! except the fact that some offers need you to pay but that is all worth it when you get that gadget that you've always wanted!

The best way to illustrate this is with a simple scenario. Imagine you are signing up in order to get yourself a free iPod Shuffle (Which would take just 2 referrals!), and decide to complete the Intuit/Worldwinner offer.
Participant Spent Received
You Intuit: Nothing
Worldwinner: 10$
Intuit: A 30 day free trial which you can cancel anytime
Worldwinner: You have fun playing games and get to earn if you win from these games
Referral Site $50 on the iPod Shuffle Thw advertiser pays commissions of around $40, adding up to about
$115. Making up to $55 profit after sending out your iPod Shuffle.
Advertiser About $115 in commisions for the said
site and compared to traditional Web,TV or marketing Campaign
Three potential customers who have tried their service and who can
therefore make an informed decision about whether or not they wish to continue using it.