The Shango Cannabis shop in Portland, Oregon, has been selling legal recreational marijuana since Oct. 1, 2015. Reuters/Steve Dipaola

For many marijuana dispensaries in Oregon, the state’s decision to legalize recreational weed in October drove scores of new customers into their stores and boosted sales. For other Oregon dispensaries, business is not so great.

According to a report by the Guardian, “oversaturation and shaky business plans” are pushing many Oregon pot dispensaries out of the market. As the state readied itself to legalize recreational marijuana, many sellers jumped into the market, thinking they'd make a killing when pot became legal for recreational purposes.

One struggling dispensary owner says revenue has been down because there are “two or three times as many stores as there had been the year before.”

Of course, not just anyone can open a store and begin selling pot. Dispensary owners first must file for a license and get approval from the state. In July, there were about 300 licensed dispensaries in Oregon, with about 400 more waiting to be approved, according to the Associated Press. Insiders say that while obtaining a dispensary license in Oregon is relatively easy, it's not necessarily a good thing for the overall industry.

“Oregon has the lowest barrier to entry than any other state that has a legal marijuana industry,” writes “Johnny Weed,” a blogger on a popular cannabis blog. “That combined with the fact that everyone and their grandma wants in on the industry is creating a very crowded Oregon cannabis scene.”

In many ways, Oregon’s pot market is a classic example of a gold -- now green -- rush. First there’s the boom, then there's a bust.

“We didn’t need all those dispensaries," Donald Morse, the director of the Oregon Cannabis Business Council, told the Guardian. "A lot of people got into it, but they were not well financed and were hanging on by their fingertips. ... The shake-out has begun.”