Actually, not so sure that all below who scream how horrible this deal is are doing the math. I sell cards every day for income, and even at cost of 20%, this aint that bad....if you care about the BTC at all.
If you care about straight cash, then doing cardpool or some online site might make more sense if you have certain cards. Walmart and Home Depot are pretty much the two cards that garner the highest resale on the secondary market, getting 85% to 92% of the value of the card at the time of resale. If you don't mind waiting 3 to 6 days for your money, obviously these percentages beat giftcarddrainer.
However, if at ALL care about the BTC, then the site makes some sense. With a little math, for a $100 Walmart card, if you get $92 cash back for it then buy BTC online at todays cash rate of about $235, you'd get about .3914 BTC ($92/$235). But you wouldn't be getting TODAY's cash rate, you'd be getting it 4 to 6 business days from now. I'll leave the time value of money and discounting out of the discussion in detail, but waiting CAN have a cost (potentially very large or not at all depending on which direction BTC price happens to move during the waiting period).
In the same scenario, if you instead did giftcarddrainer and got BTC directly from the site you'd get the daily rate today. If we merely assume for simplicity's sake that it's $235 per BTC, then the numbers work out to $100 gift card x highest fee of 19.5% plus .57 cents which yields a net of $79.93, getting about .3401 BTC ($79.93/$235). Granted, it's a difference that - if an individual is cashing out over $10K in cards - can make a big diff, but for me if I'm only cashing a couple of hundred bucks (like most folks) and market is volatile or in decline (as it has been recently), I'd rather have my BTC in 2 days to put it to work versus a few extra bucks in a possible extra 4 days as I wait for cardpool to send the check (or deposit, or paypal).
And remember, we're assuming this is with the HIGHEST resale value card. Most gift cards actually resell in the 68 to 73% range, so then giftcarddrainer makes WAYYY more sense.
And to quell any whispers, I have no investment, ownership or business interest in giftcarddrainer at all. Never even used the site (yet)...just hate to see people leap to conclusions without data.
You're welcome for the entirely too much data I just provided. :-)