[nnn1234]

You are already on the right path. Communities like hackernews and product hunt are good for early adopters Quora,FB groups and meetups are next. Online SEO AdWords will get you some traffic. Best would be have ambassadors/refferars Communities in the real world that cater to your product or service are better for RoI

[lindorna]

Being new to HN and PH, I feel like influencers' help is needed to promote the story on such communities. Is it really so? Investing lots of time to boost karma does not sound like a good strategy at first glance.

[nnn1234]

I would recommend the rest of my previous post. Online communities will get peoples attention, and at best they are a large opening to a funnel.