Licensed marijuana stores are as profitable as Starbucks stores, suggests a report released Thursday.

The study, titled “Cannabis Retail: The $23 Billion Opportunity,” is based on an analysis of BDS Analytics’ GreenEdge point of sale data. It states cannabis dispensaries could average a 12 percent after-tax profit margin, which is in line with the top profit margin specialty retail stores like Starbucks, according to a release from Arcview Market Research, which released the report.

“This report shows that retail cannabis could be as big as the iPhone. It’s clearer than ever that there is a pot of gold at the end of the rainbow for those investors and operators who are willing to deal with the uncertainties and difficulties of current regulations,” said Arcview CEO, Troy Dayton.

“Cannabis stores are unlike anything the retail world has seen since big-box stores wiped out much of the specialty store business in the 1990s,” said Arcview Market Research Editor in Chief, Tom Adams. “And because of federal prohibition, publicly traded retail companies are just going to have to stand aside while entrepreneurs pursue this unique retail opportunity.”

The report also includes detailed sample retail P&L’s illustrating the impact of the 280e IRS rule that keeps cannabis business from deducting certain expenses on profitability, and how retailers are coping by “absorbing overhead” into cost of goods. Also, competitive retail landscapes in nascent medical markets, like Florida and Michigan, and those poised to transition to adult-use, such as Massachusetts and Canada; and insights into top retailers’ strategies in mature adult-use marketplaces like Colorado and Washington.

The report concludes that adult-use markets will be nearly twice the size of the medical market by 2021, with $14.9 billion in sales.