[quickthrower2]

That was a long time ago. SO has the network effects to pull this off

[toyg]

SO can be cloned very easily nowadays. Network effects are actually getting worse with time; fewer and fewer people actually hang around SO, and it's increasingly spammed by students looking for free homework and people gaming for reputation.

As soon as SO vacates the free tier even a little bit, someone else will jump in.

[DaiPlusPlus]

SO is already cloned - every few months another new SO content farm comes along and clogs up the Google search results.