How do you identify your target audience on PH and reach out to them ahead of launch?

Finding previous launches that targeted similar audience might be helpful. We tried to do that in the past. Searched using key words and identified a few products that seemingly had a look-alike audience. Checked their comments and reached out to understand their motivation of upvoting and commenting this particular product launch. I think we managed to gather a good momentum by doing it for a few weeks ahead of our launch.

We didn't bother too much about PH users but gave a massive shout to our clients, prospects and partners asking to come and vote for us on the day! It did work well. I think some guys have used a dirty technique of scrapping PH and cold-mailing (at least I was approached like that once) which pissed me off royally. I went back to ask where did they get my email from but received absolutely zero response and asked my founder to report them. Definitely do not advise using anything like that as you're likely to generate extremely negative reaction and possibly get banned.