The Great Marijuana Mystery

According to The ArcView Group, a cannabis industry investment and research firm, legal marijuana has become the fastest growing industry in the United States after logging 74% year-over-year sales growth between 2013 and 2014.
That's the story yesterday from http://www.fool.com/investing/general/2016/04/17/the-great-marijuana-mystery-thats-likely-to-leave.aspx

The marijuana investing craze takes off Estimates from some industry researchers, such as ArcView, have suggested that the compound annual growth rate for legal marijuana could average 30% through 2020. This could, by some estimates, push the legal industry's annual sales value above the $22 billion mark -- and that's without the federal government legalizing marijuana. This estimate simply takes into account more states pushing through recreational and medical marijuana legislation with or without the assistance of the federal government.
Mesa gets a mention: data from Perfect Price across 66 large cities throughout six states (Washington, Oregon, Colorado, Arizona, Michigan, and California) shows that only four cities have less expensive legal marijuana than black market marijuana (Spokane, Wa., Aurora, Co., Denver, Co,, and Mesa, Az., for those curious). Conversely, 52 of 66 cities have price gaps of 10% or higher between legal marijuana and black market marijuana, including differences of 73% in Medford, Or., and 65% in Sacramento, Ca.