The cancellation of technology conference Mobile World Congress has left one start-up founder counting the cost in potential lost business.
Vittorio Di Mauro told the BBC the situation was "a nightmare".
Many big names pulled out of the event over concerns about the spread of coronavirus.
Organiser the GSMA said that meant it was "impossible" for the event to go ahead, adding it was a "dark day" in the history of the annual tech event.
Mr Di Mauro runs Connectlab which makes internet connected devices. His firm had spent around 50,000 euros on the conference, which he said was "a lot of money for us" but not as significant as the lack of contact with clients.
"We are very disappointed, and not just because of the money we spent but not having the chance to meet customers. Barcelona is much more than a trade show, it is a meeting point for everyone in the industry," he told the BBC.
His firm is already coping with problems related to the coronavirus outbreak as its manufacturing base is in Shenzhen, where many of the factories remain closed to stop the spread of the virus.
"These past couple of weeks have been a nightmare," he said. "This is a difficult time, like driving on the motorway and a fog descends with no visibility and you don't know what is ahead of you."
When he heard MWC was cancelled, he sent a bunch of hasty emails rearranging meetings with clients in Europe and is contemplating a trip to meet customers based in the US - all of which will mean more flights and more expense.
"I woke up and I was scratching my head about what to do. Some meetings at MWC are organised but some happen by chance, so how do we recreate that?"
However, he plans to go back to the event next year.
"Big companies may decide that they can do without Barcelona but that's not possible for companies like us. Everyone is in one place and that is very valuable," he said.
Mobile analyst Ben Wood said many smaller firms might be considering whether to attend next year because "they have had to swallow many of the costs from this year's show".
"The GSMA now needs to be careful that there is not a knock-on effect from this year's cancellation. Major companies and many attendees will be reviewing the importance of MWC to their business and the GSMA must work hard to have a clear path forward," he said.
And he pointed out the big tech players often hosted their own events - "set-piece launches where they can control the message away from the hustle and bustle of a tradeshow".
Many of those firms are now hastily arranging press conferences for new products that they had intended to show off at the conference.
Sony plans to launch its new phone - expected to be the Xperia 2 - via a YouTube video at the time the press conference was scheduled to take place.
Meanwhile, organisers of the event have been attempting to clarify why the show was cancelled amid speculation about the true reason.
"This is not about money - it's about health and safety and the reputation of our show," said Mats Granryd, director general of the GSMA.
Rumours had circulated that the organisers had wanted city officials to declare a health emergency in order to claim back expenses on insurance.
Mr Granryd described events as a "force majeure", a legal term for unforeseeable circumstances.
"There is no way you can insure yourself out of a force majeure situation."
According to its website, the GSMA takes out standard insurance cover on behalf of exhibitors, which does not cover the spread of communicable diseases unless health authorities issue travel restrictions.
The association's chief executive, John Hoffman, promised the event would be back next year.
"It is a very dark day, it is very disappointing. But we know the sun will shine," he said. "This is about our future together, and we look forward to hosting all of you, all of our partners from around the world, for MWC '21."