I believe it was Jasper Carrot who mused over Gift Vouchers.
It was something along the lines, of, someone suggested he buy one to give to a relative..his response was...
"What a good idea! And there I was, about to give him one of those awkward £10 notes, that you can only spend in every shop in England!"
They can be useful, if for example, someone gets married, then vouchers are good, as they force them to spend the money on something useful (DIY usually!), rather than fritter it away on...anything else.