This is pretty much dead. QFC, Safeway, Walmart, Fred meyer, all got killed for years and now most ask for DL number or don't let you use credit at all. There are a few places that it still works but that window is closing fast.
You can instore still at alot of places. If you have matching plactics with matching ids and working dumps then theres no reason you cant swipem.
I have had a few stores tell me they wont accept credit for gift cards. I got a walmart card in the back for 200 and an Ipad then walked to the front and tried for another 200 walmart card tand the lady stopped when she was supposed to press the credit key and she said, we dont accept credit for gift cards. I said "Shit, well, fuck it." and I turned and left.