[d1zzy]

This is why I get confused when someone on HN says it would be easy and quick for a competitor to replace Facebook or Google. It's only easy if you can support such costs year over year over a decade or more.

The amount of software and hardware solutions that get developed over that time creates a great entry barrier. That's not to say that it's impossible for a competitor to appear with a great idea and execution and over time become the next big thing, but it's critical to emphasize that it's going to take a long time of large year over year investment to get there.