Any time you do anything with buying cash equivilents (or actual coins), remember a cc company gets nervous if it looks like you're avoiding the cash advance rules, fees, and limits. A company's biggest fear is someone about to go bankrupt who is cashing out all their credit.

Coins don't charge till they're shipped and you get them next day. Always go online and get that balance down to 0 asap so it doesn't look like you're sneaking cash out.