After much experimentation, our group at the OpenEMR project found that posting project press releases/blogs on HackerNews on Saturday evenings (US - PDT) is best.
Because of the moderately low traffic, it’s possible to gain some interest (represented by upvotes) on an otherwise busy site/community. We were able to get the word out about our new software version, had a flurry of positive/useful comments (some directly from clinicians), and recruited a little over a half-dozen volunteers (healthcare-focused programmers mainly).
I highly recommend this approach (HN on Sat. evening, PDT) to the other projects here. Marketing is super critical for user-facing software and it’s important to spend time on it.
PS: Let me know if you’d like to work together (here on OpenHealthHub/public Github) on integrating your healthcare IT tool with OpenEMR! We are very cross-community focused (as evidenced by multiple dependencies on other important open source projects that we work with).