Consider that Hacker News does not advertise, and yet somehow you are here.

Hacker News does not advertise because it is a gigantic advertisement for YCombinator. This is not some sort of scurrilous accusation, they may not be constantly banging the table about it but it's not a secret.

I understand that, but the point is a good product spreads naturally.

Hacker News does not depend on me buying products from it for it's survival. If you can't see the difference in why a company cannot depend on word of mouth, then you're just really not trying to have an honest conversation.

Plenty companies don't advertise by shoving unwanted ads in people's faces.

There are plenty of companies I haven't heard of. QED

and yet they survive somehow

Many of them don't. Consider that BMW famously didn't run ads for most of its history... but now it does.

Many doing ads don't.

Hacker News depends on a constant stream of new users to keep the site alive, just like any other discussion forum. But you're right that unlike the average company this site seems to be OK with a stable but small user base and isn't aiming for unbounded exponential growth.

My dude, Hacker News is the ad.

This forum doesn't exist to get you to comment on news stories; it exists to attract tech people to YC.

Hacker News is as much an ad as a good product producing a happy customer

I think we're converging on "loss leader."

It's the way it used to be done with paper catalogues. If you're looking for a snowmobile then you go get a snowmobile catalog from a dealer who you looked up in a phonebook. But advertisers don't want to wait for somebody to decide they want a thing, they want to brainwash otherwise content people into wanting something they didn't previously want.