[mrspeaker]

It's in the faq under "can I post a job ad?" https://news.ycombinator.com/newsfaq.html

  "Another kind of job ad is reserved for YC-funded startups. These appear on the front page, but are not stories: they have no vote arrows, points, or comments. They begin part-way down and fall steadily. Only one is on the front page at a time. The rest are listed at jobs."

They pop up quite often (even multiple times for the same company).