I did this before to get a free DS. I wanted the console but didn't feel like paying for it, regardless of the fact that I had the money. I did the offers, completed them, they were updated as completed, and I got a message from the place stating that, at that time, they no longer had any DS's. Sucks right?
Not so bad, cause they sent me a check for 149.99 instead.
You just have to be careful. There are a few scam ones out there. You definitely need to read all the fine print for the offer, as well as all the fine print for the offers you sign up for. It's a decent system you can get over on, it just takes patience and diligence, which many people who try don't have, which is why they never complete everything.
Threads of Interest:
The Movie Thread: http://www.vgchartz.com/forum/thread.php?id=6880
The Crow Eating Thread: http://www.vgchartz.com/forum/thread.php?start=0&id=3886
The Betting Thread: http://www.vgchartz.com/forum/thread.php?start=0&id=7104
Custom GIFs Thread: http://www.vgchartz.com/forum/thread.php?id=18963
The Greatest Game Ever Conceived On Any Platform
Tag: "I have tasted Obi-Wan's bitter tears"