Launch HNs are curated threads that we help YC startups write, and then place on the front page. This is one of three formal things (the other two are job ads and orange usernames for alumni) that HN gives back to YC in exchange for funding it. This is in the FAQ: https://news.ycombinator.com/newsfaq.html, which is linked at the bottom of every page. There are also lots of past explanations here: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu....
We started doing Launch HNs in early 2017. You can see the complete list here: https://news.ycombinator.com/launches. The advice we give to YC startups about launching on HN is here: https://news.ycombinator.com/yli.html. The logistical parts only apply to YC cos, but the communication advice applies to everyone.
You're certainly right that not all these startups would make the front page through upvotes only, but we do work hard to write them up in a way that we hope will genuinely interest the community, and many of them end up getting a lot of upvotes and staying on the front page a long time.
We started doing Launch HNs in early 2017. You can see the complete list here: https://news.ycombinator.com/launches. The advice we give to YC startups about launching on HN is here: https://news.ycombinator.com/yli.html. The logistical parts only apply to YC cos, but the communication advice applies to everyone.
You're certainly right that not all these startups would make the front page through upvotes only, but we do work hard to write them up in a way that we hope will genuinely interest the community, and many of them end up getting a lot of upvotes and staying on the front page a long time.