I received two giftcards for Christmas and decided to knock them out today before I forgot about them.  I went to 
J.C. Penney and checked out, and the cashier said "Do you have one of the coupons?"  I said, "No, what coupon?"  She said, "I'll find one for you," and took $10 off the price.  I thanked her and then bought some more stuff with the remainder on the giftcard.  
Then I went to Kohl's.  I didn't see anything that I particularly liked, so I just picked up a Barnes & Noble giftcard for the same amount and tried to check out (I had done this a couple of years ago), but the cashier and the assistant manager said the system wouldn't take the transaction because it wasn't for "merchandise".  Call me old-fashioned, but if you're selling a product in your store, it's "merchandise."  I left without buying anything.  I guess one should beware of Kohl's gift cards.  One never knows when they'll slap a "can only be redeemed for pants on the third Thursday of May" into the giftcard fine print either.
Guess which store I'll continue to shop at?