Not that this should be a surprise to anyone -- terms and conditions of use are as complicated as US tax code these days -- but this is one of those wonderfully playful tests of legalese. I didn't make a purchase that would qualify, but if I got a letter from Gamestation nullifying their claim on my soul, I would frame it.
From the click-through terms agreement:
"By placing an order via this Web site on the first day of the fourth month of the year 2010 Anno Domini, you agree to grant Us a non transferable option to claim, for now and for ever more, your immortal soul. Should We wish to exercise this option, you agree to surrender your immortal soul, and any claim you may have on it, within 5 (five) working days of receiving written notification from gamesation.co.uk or one of its duly authorised minions."