Even as the aviation industry argues over the affordability of various advanced flight tracking systems in the aftermath of the disappearance of MH370, Flightradar24 has established itself as the go-to aircraft tracking tool for individuals, media, and even many airlines.

But it might never have existed if a Swedish travel comparison site hadn’t wanted to rank higher on Google.

As CEO Fredrik Lindahl tells us, in 2006 Swedish technology entrepreneur Mikael Robertsson and his partners needed to a gimmick to make their travel site Flygresor.se stand out on the web.

“Like everyone else in the industry, they were looking at ways to attract links to the website, to rank higher in Google. So I guess you could rate FlightRadar24 as starting as link-bait,” he says with a laugh. “That part of the website — which was basically just two [ADS-B] receivers in the Stockholm area — uploaded a screen shot of what they saw once per minute. It wasn’t anything close to what you see today. It had a very basic functionality. But still a lot of people linked to it, so much that they had to move it to a separate domain.”

Flightradar24 uses a combination of publicly available flight tracking systems, but ADS-B is at the heart of its functionality. ADS-B (Automatic Dependent Surveillance—Broadcast) automatically broadcasts an aircraft’s location and status in real-time. Though these systems are already on many aircraft, they are not universally required. All airlines operating in Europe had to have it installed on their new aircraft by January 2015, and are required to install it on older aircraft by 2017. In the US, ADS-B forms part of the FAA’s NextGen initiatives and will be required on all aircraft by 2020.

Flightradar24 takes the information collected by its network of receivers, mapping planes in the sky which can be viewed on its site and apps. Users can track a specific flight (helpful to those who want to know when to head out for the airport), aficionados can scan the skies with their mobile phones to identify a plane flying overhead, airlines can get a full picture of where their aircraft are at any time. Because the system picks up flight data as well as location, Flightradar24 can alert immediately when an aircraft is in trouble.

But coverage by each receiver is limited. For a full view of the skies, Flightradar24 had to grow its network beyond those two receivers it had in Sweden.

“The big thing was to open up the network so that other owners of the equipment owners could upload their data,” says Lindahl. “That was the big technical breakthrough. That obviously enhanced the functionality of the website because you got to see the ADS-B coverage in a lot of areas, especially in Europe at that time. That came couple of years later, 2008-2009.”

The service was still little known until 2010, its breakthrough year“[During] the Icelandic ash-cloud, media used Flightradar24 quite heavily when reporting on the situation with the air traffic being closed down. At that point, the two founders realized there might be some potential to create a business. They built an iOS app and then an Android app in 2010, but it was still very much a hobby project. Then in 2012, I was brought in and we put Flightradar24 in a separate company and started recruiting people. It has grown quickly ever since.”

Flightradar24 now consists of a team of 20 employees, mostly developers, iOS and Android and back-end, but the company also oversees a growing network of receiver hosts who help to help expand its view around the globe.

“We manufacture our own hardware with a manufacturer in Germany and send out about 50 of these receivers per week to various places around the world. We don’t sell the receivers,” says Lindahl. “We send them out to people who might apply to host them. We take a crowd-sourced approach to this. We get 50-100 applications per day from people who are interested in hosting the equipment and we then screen them and pick the locations that we think look extra interesting. At the end of the week, we send out about 50 receivers. That’s where we put most of our time and effort and definitely resources, because it is, by far, our highest costs.”

Lindahl admits that this free equipment approach gets expensive, but the company can fund it.

“The main revenue drivers are still app sales, also advertising revenue. We have well over one million users per day across the platform. We have a premium subscription, and we also have quite a few data customers. For example two of the world’s ten largest airlines are data customers of ours,” Lindahl explains.

Today, Flightradar24 has grown its network to 6,500 receivers. It provides hosts about a third of those receivers and the rest of the network relies on people who have their own equipment and feed data to Flightradar24. “More and more of these installations are professional installations including among many airports around the world,” says Lindahl. “That’s the really the main thing that’s important to us. To keep building that network of receivers.”

Crowdsourced through a network of volunteers, Flightradar24 gather vital flight data on all the key aviation events over the past few years. During the recent Germanwings tragedy, Flightradar24’s data was the first concrete and trustworthy information available, before either the airlines or the authorities could update the public.

While the FAA and other regulators around the world are working to enhance infrastructure and provide better flight tracking and air traffic control, Flightradar24 has encouraged hobbyists and members of the industry to create a reliable network. Lindahl emphasizes that Flightradar24’s information is not complete enough to guide Air Traffic Control centers, but many airlines use the service to get status on their flights.

“We know that almost all the airlines, especially outside of the US—where they have the ASDI (Aircraft Situation Display to Industry) feed—use Flightradar24. We’ve seen countless videos and pictures of operations enters where they have Flightradar24 up on screens, even in airport towers,” Lindahl tells us.

For now, Flightradar24’s owners plan to keep the company private and pursue projects which expand the service. “I don’t think there’s any desire to take it public, to be honest,” Lindahl says. “At the right price anything is for sale, I guess, but we see a lot of opportunities out there that we want to chase, so that’s all we’re seeing right now.”

Photo Credit: Flightradar24 results over the Northeast of the U.S. Flightradar24