Amazon November 2016 Hearthstone Promo
Update: Mean Street expansion is out! promotion remains 25%
Black friday is coming soon, as well as the new hearthstone expansion, but before that the current amazon november 2016 coin promotion is for 25% meaning you can start stocking up if needed in case there is any coin back. It may be that there will be pockets of time around black friday or expansion release where coin purchase bonus will be increased (though the existing is still decent) so it depends on whether you are thinking of making any purchase now.