An ideal project is one where the users are better off if others are using it too.
The train to the plane in Oslo is a great example. It’s faster, easier and nicer than driving. Its existence belies the argument for selfish chaos.
The same is true for the connected phone system. We all benefit from the fact that everyone uses the same protocol to make calls or send a text.
And the CES trade show was a hugely profitable project for decades for a similar reason. One big trade show was better than 200 competing ones…
When in doubt, look for the network effect.