About one in three travellers who flies to Changi Airport is just passing through.
Currently, those transit passengers with more than eight hours to kill before their next flight may decide to leave the airport and explore the city, confident that they can make it back in good time.
Travellers with about two or three hours in hand are likely to just hang around the terminal.
For everyone else in between, it can be quite painful waiting for five, six or seven hours to pass.
This is a key target group for Jewel Changi Airport, which welcomed its first public visitors yesterday and will open to all travellers next Wednesday.
Located where an open-air carpark used to be, it is directly connected to Terminal 1, and linked to Terminal 2 and Terminal 3 via air-conditioned travelators.
When it opens, travellers with long layovers can head to the 10-storey complex, which has more than 280 shops and restaurants, as well as an indoor waterfall and a five-storey garden with more than 2,000 trees and palms, and over 100,000 shrubs.
Jewel will also offer play attractions from June 10, such as a 50m-long suspended bridge with glass flooring, mazes and slides.
Travellers can opt for early check-in and wander around freely.
A total of 26 airlines including Singapore Airlines - representing 60 per cent of departing flights at Changi - will offer early check-in at Jewel. More airlines are expected to come on board in the coming weeks and months.
For travellers whose airlines do not offer early check-in, they can still drop their bags off at a designated area in Jewel.
Once they are done shopping, eating and relaxing, they can collect their bags and proceed to check in for their next flight.
Jewel, of course, hopes to entice not just transit passengers but all travellers flying from Changi - hoping that they will arrive a few hours before their flights to spend time and money there. The other big group is local residents.
At $1.7 billion, Changi's Jewel is not a cheap buy. It is, however, a necessary investment in the future of the Singapore air hub, and could well reap huge benefits for Changi Airport Group (CAG) and CapitaLand.
With travellers becoming more discerning and demanding, and the dogfight for premier air hub status intensifying, an airport has to be more than just a place for planes to land and take off.
The best airports in the world today are those that also provide great shopping, dining, and other facilities and services.
Hong Kong International Airport, for example, is developing the 25ha SkyCity mega integrated development, set to be completed in phases in the coming decade.
Beyond that, an airport is the first view of a country that visitors get, and is critical to a nation's brand.
The Singapore authorities have always been aware of this and, while others try to copy the formula, they seek to stay one step ahead of the competition.
CAG chief executive Lee Seow Hiang made the point when he said yesterday: "Located on the doorstep of the award-winning Changi Airport, Jewel will be a place where Singapore and the world meet."
The airport's investment in Jewel is timely, coming at a time when the demand for air travel, especially in the Asia-Pacific, is expected to grow strongly in the coming decades.
It is, however, not the only thing that Changi is doing.
Even as Jewel was being constructed, T1 received a makeover to improve its look and introduce improvements.
Check-in counters have been replaced, more self-service check-in kiosks have been installed and the baggage collection area has been expanded.
T2 is next, with upgrading works slated to start later this year.
When all the works are completed, Changi's total handling capacity will hit about 90 million travellers a year.
Beyond that, works have started at Changi East, which includes the construction of T5, a passenger terminal that will eventually be bigger than T1, T2 and T3 combined. T5 is expected to open around 2030.
If the proportion of transit travellers remains the same, then the number of those passing through Changi with time on their hands will grow exponentially. To this large group, Jewel beckons.