Works nearly site-wide with few exceptions.
Coupon/voucher has no threshold and appears to work in all region, including the UK, EU, and most Asian regions (including China?) Let everyone know in the comments if it doesn't work in any particular and a certain game.
Obviously certain AAA titles are excluded from this, including Dragon Age: Inquisition in North America and The Crew.
Use Coupon: NOVEMB-ERGMGX-20XOFF