PORTLAND — For Paul McCarrier, organizer of the Medical Marijuana Caregivers of Maine trade show on Saturday, it’s all about the economy.

Gesturing to the large conference room floor where several dozen exhibitors were selling their wares and services, McCarrier said the legalized use of marijuana to treat various ailments created an entrepreneurial bloom.

Almost all were small-business operators. Many were artisans, crafting glass pipes and T-shirts. Others were experts in the cultivation of the plant, providing advice and equipment such as grow lights, compost and greenhouses.

And, of course, there were the marijuana growers, who were well represented among the 150 or so who wandered through the trade show. Three years after a citizens initiative was passed and the state tweaked a law to create dispensaries and licenses for growers, there are 768 people cultivating the plant, six plants per patient for no more than five patients.

McCarrier compared the cottage industries that have grown around legalized medical marijuana in Maine to the many businesses that supply car manufacturers with specialized parts.

“It’s the economy of it,” he said. McCarrier noted that he had to leave his home in Belfast to find work in Portland, but thanks to being able to provide medical marijuana for patients, he was able to return and buy land and a home.

“Mainers are supplying Mainers with a needed product,” McCarrier said.

Several of those who attended and exhibited at the trade show speculated about what will happen in Maine after Colorado and Washington approved referendums legalizing the recreational use of marijuana on Nov. 6. Most believe it is merely a matter of time before a petition is circulated to put a similar referendum before Maine voters.

McCarrier didn’t want to muddy the waters with discussion of recreational use. For him, the focus of the trade show was on those whose lives are being changed for the better through access to marijuana.

Several patients at the show told the same story: After years of debilitating illness and reliance on expensive prescription medications which often had unpleasant side effects, using marijuana has lessened pain, restored appetite, mobility and vitality.

Three floors above the Holiday Inn By-The-Bay conference room, a patient lounge was set up in a small room. As the steady stream of people approached the door to get in, Scott Darville of Gardiner, a large man with a beard wearing a tie-dyed T-shirt asked each, “May I see your ID and prescription, please?”

The room is where patients can legally use marijuana, set up through consultation with local law enforcement agencies.

At two round tables, six or seven people sat, passing around a plastic tube connected with a vaporizer, a device that heats the marijuana so that it is atomized. There was only a slight smell of the plant in the air, nothing like the pungent smell of the herb when it is being smoked.

Betsy Foster, 51, was one of those sitting at the table inhaling the vapor from the tube. She said she was evicted from a motel room that was her home in Gorham after complaints about her smoking cigarettes. She does not smoke cigarettes, she said, but the smell may have been the vaporizer she uses.

Foster said she suffers from skin cancer, hepatitis C and migraines. She also is on methadone, but has been clean of heroin for a long time.

“I’ve been able to get off all the medications taking this,” she said, gesturing to the vaporizer. “It does calm me and helps me think clearer.”

Several attendees credited Alysia Melnick of ACLU Maine with helping write and advocate the law that clarified many of the issues that left Maine without a real medical marijuana network, despite voters approving the concept in 1999. Chief among the fixes to the law that followed the 2009 citizens initiative was blocking the creation of a mandatory state patient registry, which Melnick and others said discriminates against those using marijuana as medicine.

Medical marijuana is a logical issue for ACLU Maine to work on, Melnick said, because it touches on health care privacy, equal protection under law and incarceration concerns. Maine’s libertarian streak has meant strong support for her group’s position.

She also suggested that marijuana will emerge as an effective treatment for post-traumatic stress disorder among veterans.

Kyle Orce, whose Fresh Solutions LLC was an exhibitor at the trade show, said his business was one of many that worked with tradespeople and artists in the medical marijuana economy. He speculated that soon, large corporations will enter and try to dominate the market as growers, especially if recreational use is legalized in several states.