There are currently 16 states that allow some form of legalized medical marijuana, but only Colorado allows marijuana businesses to operate as such. It’s the first, and for the moment, only, for-profit marijuana marketplace in the U.S. Predictably, Colorado is in the midst of a marijuana boom. Between 2000—when Colorado voters legalized marijuana for medicinal purposes with Amendment 20—and 2008, Colorado issued roughly 2,000 medical marijuana cards to patients living in the state. By 2011 that number had jumped to over 127,000 paying customers, according to the Colorado Medical Marijuana Registry, and at least 25,000 more have applications pending.