So big, in fact, that here in South Korea, it has just born the country's latest $1 billion start-up, online budget hotel bookings platform Yanolja which means, "hey, let's play" in Korean.
It is South Korea's eighth unicorn, and has made a superstar of its once impoverished founder.
I've travelled to Seoul, to meet Yanolja's CEO, Jong Yoon Kim, to find out how he and founder, Su-Jin Lee, got the country hot for love hotels.
South Korea's relationship with the amorous accommodation hasn't always been one of affection.
Understanding its new allure requires going back to its sordid roots.
Love Hotels are a type of short-term, pay-per-hour accommodation.
They originated in Japan, where for centuries they've been providing couples a discreet place for intimacy.
But in the late 1960s, the underground industry gained prominence with the launch of the first eponymous "love hotel" in Osaka.
Adorned with a rotating neon sign, and offering guests hourly rates for a "rest," the accommodation tapped into society's growing sexual liberalization, and paved the way for a new wave of pay-per-hour love hotels — each more exotic and erotic than the last.
Love hotels – we called it motel in South Korea – motels used to be a well-known place for young couples to spend their time privately.
The industry's rise coincided with a widespread tightening of prostitution laws in Asia.
That trend didn't go unnoticed and quickly spawned negative associations of love hotels as breeding grounds for illicit activities and extramarital affairs.
But that didn't stop their international expansion.
Today, few countries have been left untouched by the craze.
The hotels' ubiquity even scored them an iconic emoji in 2015.
Back here in South Korea, love hotels rose to prominence in the late 1980s with the Seoul Olympic Games.
Their seedy associations have long been a source of embarrassment.
But in 2005, one man sought to change that.
For Yanolja founder, Su-Jin Lee, love hotels had always been a source of sanctuary.
Orphaned at a young age, Lee started as a janitor at a love hotel when he was 23.
It offered a place to stay and a steady wage.
So when an anti-prostitution law passed in 2004 threatened to kill the industry, he saw an opportunity.
I think such kind of experience is very helpful to understand the nature of the industry.
The discreet accommodations traditionally relied on walk-in customers.
So Lee started by creating an online advertising platform to attract new guests.
But it was with the launch of love hotel bookings site Yanolja in 2007, that the business really began to take off.
Yanolja, especially Su-Jin Lee, they are thinking what are the pain points nobody understands or finds out?
Lee also offered renovation services under the Yanolja franchise, which helped love hotels clean up their acts and target new customer bases.
Chief among those were two major segments: young couples and budget travelers seeking short-term accommodation.
In terms of the younger generation, we try to make kind of the playground for everything.
From many surveys, the quality of life, or quality of the happiness is very, very low because the millennials, or many generations, thought and felt that they do not enjoy enough activities.
So, we try to make people go out more frequently.
In South Korea, it's typical for young people to live with their parents until marriage.
With rising living costs and a slumping marriage rate, that phenomenon has been exacerbated.
Estimates suggest 57% of young South Koreans live at home well into adulthood, making love hotels an appealing escape for couples wanting to get away from the prying eyes of parents.
Meanwhile, growing travel appetite has boosted demand for new types of accommodation.
In South Korea, online travel sales have nearly doubled in the past five years, and the country now represents one of Asia's largest tourism markets.
Travel industry is really growing fast in South Korea.
It's because South Korean consumers' attitudes have been significantly changing as millennials put their priority on their working-life balance.
In addition, the government limited the maximum working hours to 52 hours per week from last year.
This kind of government activity also encourages travel industries.
Those trends led Yanolja to expand into its own line of regular and luxury hotels as well.
It has recorded an annual growth rate of more than 70% in the past five years.
The platform, which makes its money off of commission, has 32 million downloads and 3 million monthly active users.
It now hosts more than 20,000 partner accommodations across South Korea.
That's almost half of the country's some 46,000 registered inns and guesthouses, whose annual revenues exceed $3.6 billion.
The hotel is one of the items, but we are pursuing to realize a total package for the users.
So Yanolja is providing restaurant and activity, leisure tickets, transportation, and others.
That expansion has proven appealing for investors too.
In June 2019, a $180 million funding round pushed the company to a valuation of $1 billion, making it the latest travel-tech unicorn to join the likes of Klook, Airbnb and OYO.
I think the reason why we can be a unicorn is because Yanolja is the number one hotel in Korea.
But it's just the beginning, I think.
So, we are trying to be a number one globally.
Now Yanolja wants to tap into more growing markets.
The business has ventured into leisure bookings and now offers its renovation services to other commercial properties ranging from bookstores to healthcare centers.
It has also developed its own hotel management software to sell to partners and fuel its growth plans across Asia Pacific.
We'd like to be a global number one solution provider for the hotel and the other suppliers.
But in its mission to reinvent the love hotel, there's still one final goal Yanolja has its heart set on: an initial public offering.
That public accolade, it says, would mark the full transformation of an industry once shrouded in secrecy.
I don't know what's the best timing because we need to consider the market situation etc.