Often when ebay and similar deals come up there are lots of posts using the same coupon.
What I'm suggesting is to add a side-bar panel to the front/deals page to include coupons which are currently active and popular and allow someone to one-click through to the search to find all related deals.
This will expose the coupon feature and make it more of a priority on the site and also make people aware of new deals coming up.
Example I have mocked up is below:
http://i.imgur.com/5lBzRNc.png
The count would be the total +1 for all related deals and be used to sort.
The expires would show when the deal is ending.
And the deals count would show how many related topics are using that coupon.
Nice computer skills!