There are many sources on the internet that prove that this method of getting free gifts works. Here are a few videos:
This is proof that this person received their gift from a freebie site.
Here is a video of the BBC talking about freebie sites and how they are completely legitimate in one of their Newsnights:
Here are even more videos to help explain the concept of freebie sites and how they can benefit you:
Finally, you can sign up to the eXceem forums for help with your freebies and for proof from the thousands of members there:
This link takes you directly to the part of the site dedicated for people to put up pictures of the free gifts that they have received. The members of this fantastic forum have received over a hundred thousand pounds worth of gifts in total, like vouchers, iPods, computers, laptops, iMacs and Sony, Microsoft and Nintendo games consoles!