I used mine to buy DGCs from their site. Much easier to deal with. Had 3 x $20, so I was able to buy 3 x $100 DGCs for $80 each. There is also a thread in the Budget Board about Dining Dollars too.
I had 3 @ $20 and was able to buy 4 - $100 gift cards for $85.00. They took about a week to be issued and I just combined them to an actual gift card for ease of use.