I'd also throw in that comments can also yield a good response. A week ago, I made a comment on a high ranking post, and though it wasn't super high up, it yielded 500 visits to a site of mine that never gets traffic, got 20ish stars on the github project and some valuable user feedback on the problem. It was pretty cool.

Post in question: https://news.ycombinator.com/item?id=6247418