No way the kids actually know each other that way

So before the whole SBURB thing, John, Dave, Rose and Jade seem to have only communicated to each other through Pesterchum.

But there is NO WAY that's how they all became friends.

They just all happened to start talking online?? And got along so well they send each other packages and stuff??

That is the most unrealistic part of Homestuck. Not the game, not the aliens, the fact that they are all friends like that.

Also, how does one even do that??