Coupon Listing Options
If widget can display so can normal listing...
Why not give option to site admin to show coupons (random, latest, popular, expiring)... I don't think this requires major work on your side you already got these things in your widget you just have to give this option for normal listings in settings.
One more thing when people add coupon they add in batches so lets say I added 20 coupons from ebay now first 2 pages will be for same store. Why not functionality which will prevent more then x number of coupons coming on same page from same store (it will be good for home page and category page)...
I am just asking for possible options then flat latest cupons in feed.