I tried using PH this week. I actually submitted a hardware product (NAS) that had launched that same day, but this never surfaced on the site. On the other hand, some startups that had already launched months ago were trending. From this experience I'm guessing that most, if not all, links are hand picked, rather than community voted. It doesn't feel right.
I don't know why your submission wasn't visible (you might want to contact the PH team directly about that), but with regards to your point about the startups trending that have existed for months: it doesn't matter when you launched, it matters when you were discovered by someone who uses PH and then decides to submit you. All links are hand picked, but they're hand picked by members of the community, then voted on by the community.
> hand picked by members of the community, then voted on by the community
I'm looking over the submitters' profiles and I see many of the same people submitting different items... so I'm deducing that 'members of the community' != 'the community'.
That's because, like Hacker News, there are a relatively small amount of people who actually submit when compared to the number of people in the community as a whole. I personally subscribe to quite a lot of startup newsletters and follow people on Twitter who post product-related news, so I tend to have things to post most days. I assume it's the same for other people who also post on a regular basis.
People will use it for different things. Some will submit products, some will upvote, some will comment and get involved with the discussion, and some will do all three.
I don't know that this is true for Show HN posts (since it's a comparable product). It seems most Show HN's are posted by the creators. And Product Hunt is the other way around because most creators are not allowed to post there.
