Selling/Buying gift card websites

So I was watching the news during the holiday and they were talking about some websites that will buy gift cards and sell them too. I checked out this website www.cardpool.com and while the prices aren't like spectatular you still get a deal. Of course the drawback is that any place you would actually want to go to has more demand therefore less savings. I think its cool that you can sell your unwanted giftcards and buy ones you want a bit cheaper. What do you guys think? I know some people wouldn't trust buying giftcards online but after all the website was validated on the news.(cause everything they say is true and never put out of context) So would you guys buy these gift cards? Would you sell them? If any of you have I'd love to find out how it worked out.