Anatomy of Visa giftcards

Since I got a Visa giftcard from a competition I finally got around to ordering this.

Unfortunately Visa giftcards seem to be a right royal nuisance. Paypal won't take them, the stores here won't touch them because they aren't chip and pin, so now I'm left hoping that Amazon.co.uk will actually accept them. Just to make things even more confusing there's no way to check the balance on it without phoning the states.

All in all, it's rather annoying.