Bid4Prizes is an auction based competition, giving a chance to a lucky winner, for winning a prize (you have to provide the prize, let's say a Smartphone, who doesn't want one). To be able to play and place bids, user need to earn coins and he can do that by completing CPALead Surveys or by inviting friends (he earn an X amount of coins, by your choice, for every survey completed by his referrals).