[robko]

I question whether it is actually 75% off: if you read it closely it says "UP TO 75% off" and is described as a "mystery" code. I take that to mean you'll get somewhere between 0 and 75% off and I assume it will show you actual amount when you try to use it.

EDIT: when I actually read the whole e-mail (instead of having scanned and semi-ignored it), the fine print confirms that you will get 25-75% off when you enter it at checkout, and the usual restrictions on what it works on apply.