A lot of others have.
Mar 12, 2015
Colorado's retail marijuana sales-tax receipts increased 153 percent in January, totaling more than $3.5 million, compared with $1.4 million in January 2014, the first month that recreational marijuana was legal.
The statistics are included in the most recent report from the Colorado Marijuana Enforcement Division. The $3.5 million came from a 10 percent sales tax applied to recreational marijuana.
http://www.bizjournals.com/albuquerque/blog/morning-edition/2015/03/colorados-marijuana-sales-tax-revenue-soared-in.html