I have to say I'd agree with Fluffy about market instability. Yes, people would buy low, sell high within their own cargo, but I think as a currency for trades, minerals would be forgotten. If I'm selling let's say 100 ctp, I don't want to be bothered with timing it so that I get the maximum value. Eventually people are going to say "Eff that, credits or hard merchandise." At best, credits would become the new currency and that brings in more conversion issues. And don't even say "when the GTC is added" because it's been "coming soon" for nearly a year now.