Real and active indie hackers who engage in the community.
If they reach out to me, I expect them to have read my profile.
All automated approaches are binned / blocked right away.
My criteria for upvoting products on Product Hunt revolve around innovation and practicality. If a product introduces a novel solution or significantly improves an existing one, it earns my vote.
I mostly look for what I can use and just generally interesting ideas and concepts. I also upvote if people ask to follow on their teaser pages (I try not to forget, but things happen sometimes).
I asked the same thing some time ago and noticed that most answers were that people mostly look for products they can use for their work.
Project idea and concept as a first analysis. I then assess the communicative quality of the material and lastly study the product on the site and if possible test the product myself
For me, innovation and the potential to solve real-world problems are key criteria for upvoting products on PH. If a product can genuinely make life easier or introduce a new way of thinking, it earns my vote.