Okay according to Serebii the Global Link has announced the first attraction in the PokéMileage club for Pokémon X and Y. This attraction is called Balloon Popping and is playable on the Global Link website. The full details of this attraction aren't known, but you can apparently get items and it costs PokéMiles to play.
In addition to this they have announced a special Global Link distribution of the Discount Coupon item.
As you mentioned the Discount Coupon gives you a 50% discount in all Boutiques across the Kalos region.
This item will be distributed from the 15th of January 2014 in Japan and is one per game. Details of a North American and European distribution are not yet known.
Hope I helped :)