If your product helps people, it is your moral duty to promote it

OP here. I've spent so much time being shy about my product... Then I started getting angry at the fact that people bought from my competitors, even though they had an inferior product. Made me realize that I had learn to convince them too, and do proper marketing. People need convincing and it's not a bad thing to try and "close" them. What matters is that your product actually betters their lives.

I think if you've got good evidence that it is actually effective, it is "net better" to promote its usage.

Yes, otherwise it’ll be relegated to a research paper (maybe, because that’s also a form of promotion) in a journal.

How else would people hear about it?

In medicine, I believe, this is a large part of the reason for continuing education units.