On the display are $25 iTunes Gift Cards in pink. From 8/1/12 to 8/31/12, $25 cards are selling for $20. These are hard cards, not vouchers. I didn't read the T&C but I don't believe there was any purchase necessary.
This should not be YMMV on the deal (only inventory) as it is a nationwide promotion, as there was a corporate shelf talker (display sign) promoting the discount.
For those who don't care to buy $100 worth for $80, this is a great opportunity! Good luck!