Quick Coupon is a WordPress plugin by iintensemedia that allows you to quickly and easy offer code or discount codes on products to your visitors.
In less than 2 minutes, you can setup your site with Quick Coupon and start offering discount codes in no-time. Configure your discount codes based upon Posts or Pages, and then simply insert the Shortcode into any Page or Post to display discount code box.
View a demo online at: http://quickcoupon.iintense.com/
Download and info: http://wordpress.org/extend/plugins/quick-coupon-easily-offer-discount-coupon-codes/