A smile is
Unless your in Thailand hohoho.
A lot of the "Free Laptop" things on the internet go along the lines of getting your friends to sign up for services before you get it so it may be free for you but costs a packet for the people you know. And you have to consider the time lost convincing people to sign up which could be spent making money so really your losing out on that too.
I read the T&C of offers now and then and most of them are along the lines of "Get 10 friends to sign up for a silver deal then you will be put on gold level. Get 10 friends to sign up for gold level and you will be put on platinum level. Get 10 friends to sign up for platinum level to recieve your XBox/Laptop/Place in heaven/Whatever.
So although they aren't really scams you'd probably be better trying to convince 30 friends to all chip in and buy you a XBox. No I'm not going to chip in