“We travelled all the way to Seoul today just to try out Shake Shack, which everyone has been talking about on social media,” Kim told The Korea Herald after finishing her meal at the store on Wednesday.

“The wait was pretty long, but it was definitely worth it. The burger and the side dishes were one-of-a-kind,” she said. “I’ve just posted some of my own pictures on Instagram as well.”

Kim is one of thousands of tech-savvy, trend-sensitive Koreans in their 20s and 30s fueling the initial runaway success of the famed New York burger franchise here, where more than 3,000 burgers are sold daily and hour-long waits are typical.

Founded in 2001, Shake Shack is internationally famous for its premium, handmade burgers made with fresh ingredients as well as its side menus such as crinkle-cut fries, frozen custard and creamy milkshakes.

The brand pursues “fine casual dining,” which combines the kind of high-quality ingredients offered by upscale restaurants with the benefits of fast-food such as convenience and low pricing.

And this American burger franchise appears to have struck a chord with Korean millennials who think pricey burgers are all right as long as they are trendy and who do not mind waiting as long as they have an audience on social media.

“Koreans have developed a strong culture of ‘proving’ they went to certain places or experienced something via social networking sites, which has played a major role in fueling Shake Shack’s popularity here,” said Lee Taek-gwang, a culture critic and a professor of global communication at Kyung Hee University.

For Korean customers of Shake Shack, surviving the long lines, finally taking a bite of the juicy American burger and making it known to those around them, is worth the effort.

“Coming to Shake Shack today was like a quest of sorts for us,” said  Lee Min-young, a 24-year-old student who visited the store with friends on Wednesday. “We’ve been reading so much about these burgers online and we’re glad we finally got to try it for ourselves.

The group of friends, like most others dining inside the Shake Shack store in Gangnam, took selfies in front of the store and of the famed US burgers to prove on social media that they had braved the wait.

“Many friends who have not had a chance to come here yet, left comments saying they were eager to try out Shake Shack soon,” she said.

The US burger brand’s success here is also linked to the feeling of exclusivity associated with a visit to the restaurant, according to professor Lee.

“Hailing from the US, Shake Shack offers locals a rare opportunity to experience an authentic, high-quality American burger that stands different from the numerous other burgers sold at fast-food chains in Korea,” the culture critic said.

“Shake Shack’s burgers are fairly expensive compared to typical Korean food. However, people are willing to go for the premium US burger right now as it is considered a ‘special food’ that you can’t easily get anytime.”

Encouraged by Shake Shack’s explosive popularity in Korea, the US brand’s Korean licensee SPC Group plans to open a second Shake Shack store in Seoul within this year. The location has yet to be determined.

While Shake Shack is popular for now, professor Lee said Koreans may lose interest in the brand quicker than expected as trends here emerge and die down at an extremely fast pace.

“Once every curious Korean consumer has tried out Shake Shack, and even returned a few times, the brand’s business may decline. That may happen in as short as two years,” the culture critic said.

By Sohn Ji-young (jys@heraldcorp.com)