Received this email from Green Man Gaming this morning. Basically they are overhauling their current payment system and credit setup, and
However, this unfortunately means we’ll be closing down the current credit programme, with plans to expire all GMG credit on November 24th, 2015.
It's also on the Playfire Blog.
I have about $8 credit on GMG mainly from referrals, and have never managed to use them because you cannot use account credit and coupon code at the same time (as you can almost always get 20-25% off coupon codes). Unfortunately now I must find something to buy now, and pay full price for it (using credit).
Yeah that sucks, but it's pushed me to use the credit I'd otherwise just leave sitting there. I had $3.61 credit. Just bought DLC Quest for free. Can't complain really :)