[m3tr0s]

Start a subreddit. I mean if you want to build business, don't start with building a product if it isn't completely necessary (it isn't).

[ManlyBread]

Handing over the control to an external entity like reddit is not a good idea considering how intrusive the administration can be and how little control you yourself might have over the subreddit in case the site policies change.

[charleswzx]

In your opinion, subreddit vs. discourse/telegram/slack channel?

[m3tr0s]

Reddit, because it is indexed by search engines. Others I think are not.

[iKJames]

Discourse is a forum software, self-hosted and does get indexed by search engines.