Google Coupons are one of the great underpromoted features of Google Maps. It came, we saw and it didn’t conquer. Not because it couldn’t but it just seems to be one of those Google technologies that is languishing in the backwaters of some engineer’s 20% project.A recent query at the Google Maps for Business Group about why ValPak’s coupons were larger than his coupons got me to poking around coupons once again.What I found was a (buried) upgraded local like interface that allows a users to search for all coupons in a given area or all coupons in a certain industry in an area. For example you may search on “all coupons in Olean NY” or “restaurant coupons in Buffalo NY.Why coupons continue to be the poor step child in Google’s local arsenal is beyond me. Google could easily provide an interface to allow websites to embed these coupons either via an api, rss feed or an iframe (like Maps). This would at least offer the coupons some visibility and a way out of the dark basement of Google Maps.In September the InsideGoogle Blog noted a slew of new Google Coupon domains including Google-Coupons.com and CouponGoogle.com are now registered and controlled by Google. Perhaps this new (maybe its not new but it is obviously hard to find) interface upgrade and the new domains portend the first step in rolling out a more prominent coupon program.