There's Show HN, ProductHunt, meetups, connections (which you can get through meetups), pitching events/contests, sponsorships, influencers... Part of it may c

There's Show HN, ProductHunt, meetups, connections (which you can get through meetups), pitching events/contests, sponsorships, influencers... Part of it may come from designing the product to help with the marketing. That may also help with viral marketing. Marketing is a pretty broad topic, and it can vary a lot, too. Maybe it's a good idea to talk to some of your customers face to face to learn more about their industry vertical. If you share some specifics, maybe more people here could suggest ideas.