“Though he was only the seventh person in the city of Denver to apply for a license, the constant changes mean that he won’t be able to open until about January 10, over a week beyond the official start of recreational marijuana sales. The process has been similar for dispensary owners all over Denver, which means it might be one of the few places where a legal retail marijuana shortage will happen right away. The licensing for retail locations and retail grows is happening at the same time. This would be a problem for those trying to open on January 1, except that the state has allowed a one-time transfer of medical marijuana to retail. This transfer is how all stores will start.”
http://stopthedrugwar.org/chronicle/2013/dec/31/legal_marijuana_no_simple_matter