In a recent interview with the founder of Zwift, Eric Min, he brought up how they hacked Strava in the early days, to achieve growth.
For some background, Strava has more than 100m athletes using it as of today.
Since the folks at Zwift knew that Strava has the GPS feature displaying where the athletes are riding on the map, they used Jarvis Island, a small Airfield in the South Pacific last used in World War II, that was uninhabited.
By using Zwift, people appeared as if they were riding on Jarvis Island, which made their friends wonder, and everyone started commenting.
So Zwift gained popularity in Jarvis through word of mouth
See the video here!