And as more states legalize cannabis, the Marijuana Business Daily forecasts that figure just might hit $8 billion by 2018.
Colorado is already a big piece of that pie. Total sales last year here nearly reached $1 billion.
So how does the marijuana industry compare to others, sales-wise? As Quartz points out, legal pot last year outsold Girl Scout cookies and e-cigarettes. But it's got a ways to go to overtake snacks like Doritos and Cheetos; Americans bought $4.9 billion worth of such snacks last year.