Self serve app for serving ads/coupons

hey guys... i'm at a complete loss here. working on a project and the owner is looking for a way to allow people who he partners with (his advertisers) a way to be able to provide coupons to users who come to the site. he wants a self serve solution for the advertiser, so the advertiser can create their own coupon(s), and then the user coming to the site can see the coupons that are available, and select the ones that they want to get. the app could also allow the coupons to be sent to/emailed to the users who've opted-in.. i've been searching all over the place.. anybody have any thoughts on where this kind of tech might be??? thanks