YCombinator, the accelerator which invests in startups, is a money printer. Any tiny amount of money generated by ads on Hacker News would be a rounding error.

The site does technically show ads. YCombinator companies can post job ads here. The job ads are privileged in that users are not allowed to comment on them.

Now that I think about it, I haven't seen many job postings from YCombinator companies in a long time. Though to be honest, after some of my experiences with applicants from postings I put in the "Who's hiring" threads I could see why they this site might have fallen out of favor as a hiring location.