Do you think tracking passengers via their mobile phones is a good idea?
Helsinki's airport will be the world's first to track passengers to within feet, a plan being hailed as a technological breakthrough - and drawing scrutiny from privacy advocates.
Sensors will monitor all mobile phones with Wi-Fi access turned on from parking lot to takeoff, helping to observe crowding and prevent bottlenecks at the two-terminal airport which 15 million fliers pass through a year.
Passengers opting in through an application will also receive offers from shops and restaurants, as well as gate and flight information.
While the technology has clear benefits, companies must tread carefully to adopt it as such systems can be perceived as enabling the monitoring of unwary people.
US-based retailer Nordstrom ended a tracking test last year after a backlash from disgruntled customers.
"The fact that my movements are tracked is a scarier thought than someone knowing which websites I visit," Antti Tikkanen, director of security response at software maker F- Secure, said in an phone interview.
"I have a hard time believing location tracking is only left at statistics when the same technology makes so many other things possible."
Walkbase, based in Espoo, Finland, is providing the indoor-positioning system for the airport.
Such systems are being deployed more widely as physical shops seek to remove a disadvantage against online retailers who are more advanced in analysing the digital traces left by customers.
The Helsinki airport operator, Finavia, won't see any personal information about the user or the device as all data stays in an aggregated form, said Tuomas Wuoti, chief executive officer of closely held Walkbase.
The software also discards the unique identifiers of devices after pulling out the necessary data, he said.
About 150 white boxes the size of a Web router are set up around the airport to collect the unique identifier number called the MAC address from devices searching for Wi-Fi networks. They then scramble the information and send it onward to servers.
"We're looking at great paybacks from this investment," Heikki Koski, vice president in charge of new services at Finavia, said in an interview. "We can manage the airport better, we can predict where bottlenecks might come and analyze everything more thoroughly."
Privacy concerns mean earning passengers' trust is "extremely important" to Finavia and the anonymous monitoring respects customers' privacy, Koski said.
Citing experience from retailers and initial trials at the airport, Walkbase expects about 60 to 70 per cent of people to leave their Wi-Fi access on, making predictive analytics possible.
"It's not that interesting to know whether there are 100 or 150 people somewhere," Wuoti said in an interview at the airport as afternoon traffic was steadily picking up pace. "What's interesting is to understand will it be congested."
While similar systems are used at parts of other airports, Helsinki will be the first one with full pinpoint coverage throughout its premises, Wuoti said.
The initial tracking system is in place, and the airport is adding the capability for marketing messages to people who opt in via their application of choice, such as that of an airline or retailer. The airport has 35 shops, including fashion, electronics and food stores, and 32 restaurants and cafes.
The complete system, in place by the end of the year, may allow a delicacy shop to alert those walking by about a reindeer jerky offer or tell a traveller to Tokyo that there's just enough time for sushi before she needs to start walking to the gate.
"When people are coming in they might be newcomers to the airport," Koski said. "It's good to know you have that extra 15 minutes to look for something for your spouse or your family."