It works great, but you quickly get coupon overload. There are well over 20 coupon sites in Buenos Aires now - Groupon, Agrupate, Pez Urbano, ClubCupon, etc. I think all of them require a national credit card too.

I like that they added Groupon Shopping. We've bought a few household items from them, but as for coupons, we only buy when they deliver or it's near us.

Try these coupon aggregator sites too - Cuponica and Oony. They make it all a bit easier.