In all seriousness, I've done one of those ad sites before - it is how I got my 42 in tv. It isn't free (not close either) because the requirements all have you spend on shipping and starter trials that in a week or two will prompt something much more expensive. They do work, though - read all the fine print.
The problem though, mazic, is even if this is your best option to get a wii - these sites have a right to substitute something of equal value. If Wiis are still rare, you might still not get one. And I would predict this is going to take you 6 months to a year best case scenario. It would really be better to get a job for something that is 250 dollars, srsly.