Shooting the video in temperatures of -5C after a long night at the festival put on by Umeå to celebrate the end of its year as a European Capital of Culture, I'll be honest, former Deputy Editor Oliver Gee (who's now based at The Local France) and I had no idea our report would be such an international success.
We knew those of you who are regular readers of The Local would love it, just as you've snapped up our stories about other Swedish quirks, from having to hug your boss to not sharing alcohol at parties. And don't get Oliver started on the word Göteborg.
But we couldn't have predicted that in just seven days our film - made on a smartphone - would have got almost 900,000 hits, been all over newspapers and social media in Sweden after an initial report by SVT and featured in international media ranging from the UK's Daily Mirror to Australia's News.au and Fox News in the US.
"The way people in one town in Sweden say 'Yes' is absolutely bonkers," wrote Irish news site entertainment.ie on Thursday, while backpacker site Travelpulse said "those folks might as well be saying 'sure, that will be just fine' in Klingon."
If you still haven't seen the video (and why not?), rather than saying 'ja' like most Swedes do, people living in northern Sweden make a noise that is a kind of gasp that could suggest the person listening to you is either impressed, shocked or a bit chilly.
A quick trawl through the comments section below the video on YouTube suggests that above all, the video is popular because it made people laugh.
"This is hilarious to me! I brought my American boyfriend to the north of Sweden where I'm from and he thought my Dad had a breathing problem when he said yes this way," said one post.
While Swede Olag Johansson quipped that the title of video was misleading, dubbing it instead "the most awesome sound".
On Reddit, a site which collates viral stories, another commentator joked that in northern Sweden, having (good) sex with someone might sound like "an asthma attack."
A snapshot of our coverage on Google News. Photo: The Local
Speaking to The Local on Friday, the mayor of Umeå Marie-Louise Rönnmark said: "Umeå always surprises! Umeå is a fantastic place where humour creates a certain kind of confidence. People are welcome here!".
Another contact at the tourist office, who did not want to be named, joked that she could envisage thousands showing up in the city and asking locals to make the sound.
Frederick Lindengren, Artistic Director of Umeå 2014, said: "'Schwup' is the answer to many big questions," adding that it could even help "boost international diplomacy." No we're not sure what he means either. We told you those people in northern Sweden were rather unusual.
Some of The Local's news team in Umeå: Editor Maddy Savage (left), intern Mimmi Nilsson and reporter Oliver Gee. Photo: The Local
Here at The Local we're especially proud that we shot the video on a smartphone, proving that our small but rapidly growing news brand doesn't need expensive equipment or camera crews to make the kind of content that our unique international audience enjoys watching.
"It's great that Oliver's video has made people around the world so curious about the wonderful Swedish language," said our Managing Editor James Savage on Friday.
"The Local is all about bridging different cultures, and what better way to connect with people than learning to say 'Yes'? Our nine European sites will be doing many more videos like this in the months to come."