Actually this just adds to the number of places where marijuana is legally sold in a public setting.
Californians have been legally buying & selling cannabis to "medical users" for 16 yrs now. Upwards of a million residents routinely buy & sell weed under very easy to use rules and in recent years the state is collecting tens od millions in annual tax revenue from that biz.
The state of Washington also legalized in full for adults 21+ beginning Jan 1, 2014.