People on HN won't like that you do this but at least you're honest, and showing that this does actually happen, it's just that others are not so loud (at least sometimes, see the link below). This sort of thing is very common on reddit, there are even articles and studies about said astroturfing.
Due to the cyclical nature of posts and the exhausted moderators trying to mod all of them, it's quite effective for "organic" growth. Many companies use these methods to grow, because it's way cheaper than paying for ads and users online are simply too gullible to catch on. And even if they did, you can just delete the thread and make a new one later on.
It's the same strategy used in TikTok where the influencer subtly hints at the product rather than overtly talking about it (perhaps as one slide in a slideshow), and then when a commenter asks what they used, the influencer replies with the name of the product.
For example [0], there have been large scale astroturfing campaigns for things like games, posting large numbers of comments to influence users.
[0] https://old.reddit.com/r/Games/comments/1ot0nvg/game_dev_adm...
Personally I don't like that they do that, not that they are pointing out that they do that.
Yes I should've said, people on HN don't like that they do that, or that it happens at all, but the reality is that it does and especially for people on a forum run by a startup accelerator in particular (with tons of Ask HN questions on how to grow their product via marketing), posting on social media is one of the most effective ways to grow, whether people like it or not.