After all, this is the first CES since marijuana was legalized in the state of Nevada last year, and it's available for purchase all over Las Vegas. The irony is that in Sin City, you are prohibited from consuming cannabis products anywhere but in a private residence, including hotels, parks and even dispensaries.

In practice, vaporized cannabis and edibles are easy to find and easier to consume with little residual smell (there was no hint of weed vapor in the Mirage's hallway on Monday). But technically, a combination of state law and hotel policy means that Vegas' visitors -- of which there were 42.2 million in 2017 -- lack almost anywhere to take advantage of legal cannabis.

It also means that the few cannabusinesses at this year's CES are also hamstrung in their ability to demonstrate their products, even as there's a gold rush of demand that led to cannabis startups receiving more than $600 million in equity funding last year. Hence Puffco's after-hours session at the Mirage.

"We think that if you want to make an omelet you've got to crack a few eggs, and so that's why we did this in here," said the Brooklyn-based Volodarsky, on using his suite for demos. "For us it's just the risk we take, and if they want to kick us out for it I'm OK with that."

In contrast, Vapium, another vape company, presented at CES with a different angle: as a strictly medical company. Located in CES' smart home section around companies hawking gas sensors and smart pet doors, its booth was a clean green and white with representatives wearing white lab coats.

Under the brand Vapium Medical, the company launched a smart vape that tells you precisely how much THC or CBD you consume with every inhalation. It achieves this by cross-referencing the airflow through the vape and the exact strain and strength of the cannabis capsules inside it. Pinpointing effective dosages of medical cannabis can allow doctors to prescribe it more accurately and monitor a patient's use, all while creating a database about how certain strains and quantities of marijuana use affect certain medical conditions.

"Even for doctors who are convinced that cannabis is effective, there's not really good dosing guidelines," said Barry Fogarty, Vapium Medical's COO. "Because it's been a prohibited substance in most places, there hasn't been the research that there needs to be, and so that's exactly what we're trying to plug into."

Due to release in the second half of 2018, Vapium Medical is presenting the prototype purely as a medical device. "We'll only sell products in those states where medical cannabis is legal," said Fogarty.

There would not be any demos at the trade show either. "Especially as a medical company, we will adhere to all of the bylaws," said CMO Lisa Harun.

For Puffco, the decision to come to Vegas was only made four days in advance.

"We thought, why not show this off at CES? It seems like a place where maybe new eyes that have a respect for great design and strides in industry, maybe they'll respect us there," said Volodarsky. "It's easy to be a marketing company in cannabis. It's much more difficult to be an innovator. And the risk is high just like in any other side of consumer electronics."

That risk extends to its off-site presentation. "It is what it is," said Volodarsky. "This is the unfortunate risk we take as leaders of the industry; it's what we have to do."

The showcase ended when Puffco's spokesman got hungry ("He's done a few demos," Voladarsky said) and they headed out for pancakes. Before leaving, Volodarsky grabbed the rig for one more hit.

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