When deal is marked as store offer by its creator, then price you see is price for voucher, once you purchase it you can go to store and redeem your discount.
Why Sales Are Required?
This type of deal requires minumum number of sales defined by the deal vendor during the deal submission. Once the number of purchases becomes equal or higher than the defined minimum number of sales, deal is activated and you will receive voucher to reedem your discount.
If deal did not acquired defined minimum number of sales and it is expired or deleted, you will receive full refund.